From: Zhu Yi <yi.zhu@xxxxxxxxx>
Resend. Replace mail subject due to ML restriction for capital Triple-X
in subject.
On Thu, 2007-11-29 at 11:09 +0800, Zhu Yi wrote:
From: Cahill, Ben M <ben.m.cahill@xxxxxxxxx>
Add comments to iwlXXXX-base.c
Signed-off-by: Cahill, Ben M <ben.m.cahill@xxxxxxxxx>
Signed-off-by: Zhu Yi <yi.zhu@xxxxxxxxx>
---
drivers/net/wireless/iwlwifi/iwl3945-base.c | 215 ++++++++++++++++++++++-----
drivers/net/wireless/iwlwifi/iwl4965-base.c | 209 ++++++++++++++++++++++----
2 files changed, 354 insertions(+), 70 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 775f9a1..1808464 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -63,13 +63,13 @@ static int iwl3945_tx_queue_update_write_ptr(struct iwl3945_priv *priv,
******************************************************************************/
/* module parameters */
-static int iwl3945_param_disable_hw_scan;
-static int iwl3945_param_debug;
-static int iwl3945_param_disable; /* def: enable radio */
+static int iwl3945_param_disable_hw_scan; /* def: 0 = use 3945's h/w scan */
+static int iwl3945_param_debug; /* def: 0 = minimal debug log messages */
+static int iwl3945_param_disable; /* def: 0 = enable radio */
static int iwl3945_param_antenna; /* def: 0 = both antennas (use diversity) */
-int iwl3945_param_hwcrypto; /* def: using software encryption */
-static int iwl3945_param_qos_enable = 1;
-int iwl3945_param_queues_num = IWL_MAX_NUM_QUEUES;
+int iwl3945_param_hwcrypto; /* def: 0 = use software encryption */
+static int iwl3945_param_qos_enable = 1; /* def: 1 = use quality of service */
+int iwl3945_param_queues_num = IWL_MAX_NUM_QUEUES; /* def: 8 Tx queues */
/*
* module name, copyright, version, etc.
@@ -184,17 +184,24 @@ static void iwl3945_print_hex_dump(int level, void *p, u32 len)
*
* Theory of operation
*
- * A queue is a circular buffers with 'Read' and 'Write' pointers.
- * 2 empty entries always kept in the buffer to protect from overflow.
+ * A Tx or Rx queue resides in host DRAM, and is comprised of a circular buffer
+ * of buffer descriptors, each of which points to one or more data buffers for
+ * the device to read from or fill. Driver and device exchange status of each
+ * queue via "read" and "write" pointers. Driver keeps minimum of 2 empty
+ * entries in each circular buffer, to protect against confusing empty and full
+ * queue states.
+ *
+ * The device reads or writes the data in the queues via the device's several
+ * DMA/FIFO channels. Each queue is mapped to a single DMA channel.
*
* For Tx queue, there are low mark and high mark limits. If, after queuing
* the packet for Tx, free space become < low mark, Tx queue stopped. When
* reclaiming packets (on 'tx done IRQ), if free space become > high mark,
* Tx queue resumed.
*
- * The IWL operates with six queues, one receive queue in the device's
- * sram, one transmit queue for sending commands to the device firmware,
- * and four transmit queues for data.
+ * The 3945 operates with six queues: One receive queue, one transmit queue
+ * (#4) for sending commands to the device firmware, and four transmit queues
+ * (#0-3) for data tx via EDCA. An additional 2 HCCA queues are unused.
***************************************************/
static int iwl3945_queue_space(const struct iwl3945_queue *q)
@@ -213,13 +220,21 @@ static int iwl3945_queue_space(const struct iwl3945_queue *q)
return s;
}
-/* XXX: n_bd must be power-of-two size */
+/**
+ * iwl3945_queue_inc_wrap - increment queue index, wrap back to beginning
+ * @index -- current index
+ * @n_bd -- total number of entries in queue (must be power of 2)
+ */
static inline int iwl3945_queue_inc_wrap(int index, int n_bd)
{
return ++index & (n_bd - 1);
}
-/* XXX: n_bd must be power-of-two size */
+/**
+ * iwl3945_queue_dec_wrap - increment queue index, wrap back to end
+ * @index -- current index
+ * @n_bd -- total number of entries in queue (must be power of 2)
+ */
static inline int iwl3945_queue_dec_wrap(int index, int n_bd)
{
return --index & (n_bd - 1);
@@ -234,12 +249,17 @@ static inline int x2_queue_used(const struct iwl3945_queue *q, int i)
static inline u8 get_cmd_index(struct iwl3945_queue *q, u32 index, int is_huge)
{
+ /* This is for scan command, the big buffer at end of command array */
if (is_huge)
- return q->n_window;
+ return q->n_window; /* must be power of 2 */
+ /* Otherwise, use normal size buffers */
return index & (q->n_window - 1);
}
+/**
+ * iwl3945_queue_init - Initialize queue's high/low-water and read/write indexes
+ */
static int iwl3945_queue_init(struct iwl3945_priv *priv, struct iwl3945_queue *q,
int count, int slots_num, u32 id)
{
@@ -268,11 +288,16 @@ static int iwl3945_queue_init(struct iwl3945_priv *priv, struct iwl3945_queue *q
return 0;
}
+/**
+ * iwl3945_tx_queue_alloc - Alloc driver data and TFD CB for one Tx/cmd queue
+ */
static int iwl3945_tx_queue_alloc(struct iwl3945_priv *priv,
struct iwl3945_tx_queue *txq, u32 id)
{
struct pci_dev *dev = priv->pci_dev;
+ /* Driver private data, only for Tx (not command) queues,
+ * not shared with device. */
if (id != IWL_CMD_QUEUE_NUM) {
txq->txb = kmalloc(sizeof(txq->txb[0]) *
TFD_QUEUE_SIZE_MAX, GFP_KERNEL);
@@ -284,6 +309,8 @@ static int iwl3945_tx_queue_alloc(struct iwl3945_priv *priv,
} else
txq->txb = NULL;
+ /* Circular buffer of transmit frame descriptors (TFDs),
+ * shared with device */
txq->bd = pci_alloc_consistent(dev,
sizeof(txq->bd[0]) * TFD_QUEUE_SIZE_MAX,
&txq->q.dma_addr);
@@ -306,6 +333,9 @@ static int iwl3945_tx_queue_alloc(struct iwl3945_priv *priv,
return -ENOMEM;
}
+/**
+ * iwl3945_tx_queue_init - Allocate and initialize one tx/cmd queue
+ */
int iwl3945_tx_queue_init(struct iwl3945_priv *priv,
struct iwl3945_tx_queue *txq, int slots_num, u32 txq_id)
{
@@ -313,9 +343,14 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv,
int len;
int rc = 0;
- /* allocate command space + one big command for scan since scan
- * command is very huge the system will not have two scan at the
- * same time */
+ /*
+ * Alloc buffer array for commands (Tx or other types of commands).
+ * For the command queue (#4), allocate command space + one big
+ * command for scan, since scan command is very huge; the system will
+ * not have two scans at the same time, so only one is needed.
+ * For data Tx queues (all other queues), no super-size command
+ * space is needed.
+ */
len = sizeof(struct iwl3945_cmd) * slots_num;
if (txq_id == IWL_CMD_QUEUE_NUM)
len += IWL_MAX_SCAN_SIZE;
@@ -323,6 +358,7 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv,
if (!txq->cmd)
return -ENOMEM;
+ /* Alloc driver data array and TFD circular buffer */
rc = iwl3945_tx_queue_alloc(priv, txq, txq_id);
if (rc) {
pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd);
@@ -334,8 +370,11 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv,
/* TFD_QUEUE_SIZE_MAX must be power-of-two size, otherwise
* iwl3945_queue_inc_wrap and iwl3945_queue_dec_wrap are broken. */
BUILD_BUG_ON(TFD_QUEUE_SIZE_MAX & (TFD_QUEUE_SIZE_MAX - 1));
+
+ /* Initialize queue high/low-water, head/tail indexes */
iwl3945_queue_init(priv, &txq->q, TFD_QUEUE_SIZE_MAX, slots_num, txq_id);
+ /* Tell device where to find queue, enable DMA channel. */
iwl3945_hw_tx_queue_init(priv, txq);
return 0;
@@ -346,8 +385,8 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv,
* @txq: Transmit queue to deallocate.
*
* Empty queue by removing and destroying all BD's.
- * Free all buffers. txq itself is not freed.
- *
+ * Free all buffers.
+ * 0-fill, but do not free "txq" descriptor structure.
*/
void iwl3945_tx_queue_free(struct iwl3945_priv *priv, struct iwl3945_tx_queue *txq)
{
@@ -367,19 +406,21 @@ void iwl3945_tx_queue_free(struct iwl3945_priv *priv, struct iwl3945_tx_queue *t
if (q->id == IWL_CMD_QUEUE_NUM)
len += IWL_MAX_SCAN_SIZE;
+ /* De-alloc array of command/tx buffers */
pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd);
- /* free buffers belonging to queue itself */
+ /* De-alloc circular buffer of TFDs */
if (txq->q.n_bd)
pci_free_consistent(dev, sizeof(struct iwl3945_tfd_frame) *
txq->q.n_bd, txq->bd, txq->q.dma_addr);
+ /* De-alloc array of per-TFD driver data */
if (txq->txb) {
kfree(txq->txb);
txq->txb = NULL;
}
- /* 0 fill whole structure */
+ /* 0-fill queue descriptor structure */
memset(txq, 0, sizeof(*txq));
}
@@ -392,6 +433,11 @@ const u8 iwl3945_broadcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
/**************************************************************/
#if 0 /* temporary disable till we add real remove station */
+/**
+ * iwl3945_remove_station - Remove driver's knowledge of station.
+ *
+ * NOTE: This does not remove station from device's station table.
+ */
static u8 iwl3945_remove_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap)
{
int index = IWL_INVALID_STATION;
@@ -428,6 +474,12 @@ out:
return 0;
}
#endif
+
+/**
+ * iwl3945_clear_stations_table - Clear the driver's station table
+ *
+ * NOTE: This does not clear or otherwise alter the device's station table.
+ */
static void iwl3945_clear_stations_table(struct iwl3945_priv *priv)
{
unsigned long flags;
@@ -440,7 +492,9 @@ static void iwl3945_clear_stations_table(struct iwl3945_priv *priv)
spin_unlock_irqrestore(&priv->sta_lock, flags);
}
-
+/**
+ * iwl3945_add_station - Add station to station tables in driver and device
+ */
u8 iwl3945_add_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap, u8 flags)
{
int i;
@@ -486,6 +540,7 @@ u8 iwl3945_add_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap, u8
station->used = 1;
priv->num_stations++;
+ /* Set up the REPLY_ADD_STA command to send to device */
memset(&station->sta, 0, sizeof(struct iwl3945_addsta_cmd));
memcpy(station->sta.sta.addr, addr, ETH_ALEN);
station->sta.mode = 0;
@@ -504,6 +559,8 @@ u8 iwl3945_add_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap, u8
le16_to_cpu(station->sta.rate_n_flags);
spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
+
+ /* Add station to device's station table */
iwl3945_send_add_station(priv, &station->sta, flags);
return index;
@@ -673,6 +730,8 @@ static int iwl3945_enqueue_hcmd(struct iwl3945_priv *priv, struct iwl3945_host_c
fix_size, q->write_ptr, idx, IWL_CMD_QUEUE_NUM);
txq->need_update = 1;
+
+ /* Increment and update queue's write index */
q->write_ptr = iwl3945_queue_inc_wrap(q->write_ptr, q->n_bd);
ret = iwl3945_tx_queue_update_write_ptr(priv, txq);
@@ -1511,7 +1570,7 @@ static void get_eeprom_mac(struct iwl3945_priv *priv, u8 *mac)
/**
* iwl3945_eeprom_init - read EEPROM contents
*
- * Load the EEPROM from adapter into priv->eeprom
+ * Load the EEPROM contents from adapter into priv->eeprom
*
* NOTE: This routine uses the non-debug IO access functions.
*/
@@ -1536,6 +1595,7 @@ int iwl3945_eeprom_init(struct iwl3945_priv *priv)
return -ENOENT;
}
+ /* Make sure driver (instead of uCode) is allowed to read EEPROM */
rc = iwl3945_eeprom_acquire_semaphore(priv);
if (rc < 0) {
IWL_ERROR("Failed to acquire EEPROM semaphore.\n");
@@ -2631,21 +2691,23 @@ static void iwl3945_build_tx_cmd_basic(struct iwl3945_priv *priv,
cmd->cmd.tx.next_frame_len = 0;
}
+/**
+ * iwl3945_get_sta_id - Find station's index within station table
+ */
static int iwl3945_get_sta_id(struct iwl3945_priv *priv, struct ieee80211_hdr *hdr)
{
int sta_id;
u16 fc = le16_to_cpu(hdr->frame_control);
- /* If this frame is broadcast or not data then use the broadcast
- * station id */
+ /* If this frame is broadcast or management, use broadcast station id */
if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) ||
is_multicast_ether_addr(hdr->addr1))
return priv->hw_setting.bcast_sta_id;
switch (priv->iw_mode) {
- /* If this frame is part of a BSS network (we're a station), then
- * we use the AP's station id */
+ /* If we are a client station in a BSS network, use the special
+ * AP station entry (that's the only station we communicate with) */
case IEEE80211_IF_TYPE_STA:
return IWL_AP_ID;
@@ -2656,11 +2718,12 @@ static int iwl3945_get_sta_id(struct iwl3945_priv *priv, struct ieee80211_hdr *h
return sta_id;
return priv->hw_setting.bcast_sta_id;
- /* If this frame is part of a IBSS network, then we use the
- * target specific station id */
+ /* If this frame is going out to an IBSS network, find the station,
+ * or create a new station table entry */
case IEEE80211_IF_TYPE_IBSS: {
DECLARE_MAC_BUF(mac);
+ /* Create new station table entry */
sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
if (sta_id != IWL_INVALID_STATION)
return sta_id;
@@ -2746,6 +2809,8 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv,
spin_unlock_irqrestore(&priv->lock, flags);
hdr_len = ieee80211_get_hdrlen(fc);
+
+ /* Find (or create) index into station table for destination station */
sta_id = iwl3945_get_sta_id(priv, hdr);
if (sta_id == IWL_INVALID_STATION) {
DECLARE_MAC_BUF(mac);
@@ -2767,30 +2832,52 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv,
__constant_cpu_to_le16(IEEE80211_SCTL_FRAG));
seq_number += 0x10;
}
+
+ /* Descriptor for chosen Tx queue */
txq = &priv->txq[txq_id];
q = &txq->q;
spin_lock_irqsave(&priv->lock, flags);
+ /* Set up first empty TFD within this queue's circular TFD buffer */
tfd = &txq->bd[q->write_ptr];
memset(tfd, 0, sizeof(*tfd));
control_flags = (u32 *) tfd;
idx = get_cmd_index(q, q->write_ptr, 0);
+ /* Set up driver data for this TFD */
memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl3945_tx_info));
txq->txb[q->write_ptr].skb[0] = skb;
memcpy(&(txq->txb[q->write_ptr].status.control),
ctl, sizeof(struct ieee80211_tx_control));
+
+ /* Init first empty entry in queue's array of Tx/cmd buffers */
out_cmd = &txq->cmd[idx];
memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr));
memset(&out_cmd->cmd.tx, 0, sizeof(out_cmd->cmd.tx));
+
+ /*
+ * Set up the Tx-command (not MAC!) header.
+ * Store the chosen Tx queue and TFD index within the sequence field;
+ * after Tx, uCode's Tx response will return this value so driver can
+ * locate the frame within the tx queue and do post-tx processing.
+ */
out_cmd->hdr.cmd = REPLY_TX;
out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) |
INDEX_TO_SEQ(q->write_ptr)));
- /* copy frags header */
+
+ /* Copy MAC header from skb into command buffer */
memcpy(out_cmd->cmd.tx.hdr, hdr, hdr_len);
- /* hdr = (struct ieee80211_hdr *)out_cmd->cmd.tx.hdr; */
+ /*
+ * Use the first empty entry in this queue's command buffer array
+ * to contain the Tx command and MAC header concatenated together
+ * (payload data will be in another buffer).
+ * Size of this varies, due to varying MAC header length.
+ * If end is not dword aligned, we'll have 2 extra bytes at the end
+ * of the MAC header (device reads on dword boundaries).
+ * We'll tell device about this padding later.
+ */
len = priv->hw_setting.tx_cmd_len +
sizeof(struct iwl3945_cmd_header) + hdr_len;
@@ -2802,15 +2889,20 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv,
else
len_org = 0;
+ /* Physical address of this Tx command's header (not MAC header!),
+ * within command buffer array. */
txcmd_phys = txq->dma_addr_cmd + sizeof(struct iwl3945_cmd) * idx +
offsetof(struct iwl3945_cmd, hdr);
+ /* Add buffer containing Tx command and MAC(!) header to TFD's
+ * first entry */
iwl3945_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len);
if (!(ctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
iwl3945_build_tx_cmd_hwcrypto(priv, ctl, out_cmd, skb, 0);
- /* 802.11 null functions have no payload... */
+ /* Set up TFD's 2nd entry to point directly to remainder of skb,
+ * if any (802.11 null frames have no payload). */
len = skb->len - hdr_len;
if (len) {
phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len,
@@ -2818,13 +2910,16 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv,
iwl3945_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, len);
}
- /* If there is no payload, then only one TFD is used */
if (!len)
+ /* If there is no payload, then we use only one Tx buffer */
*control_flags = TFD_CTL_COUNT_SET(1);
else
+ /* Else use 2 buffers.
+ * Tell 3945 about any padding after MAC header */
*control_flags = TFD_CTL_COUNT_SET(2) |
TFD_CTL_PAD_SET(U32_PAD(len));
+ /* Total # bytes to be transmitted */
len = (u16)skb->len;
out_cmd->cmd.tx.len = cpu_to_le16(len);
@@ -2854,6 +2949,7 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv,
iwl3945_print_hex_dump(IWL_DL_TX, (u8 *)out_cmd->cmd.tx.hdr,
ieee80211_get_hdrlen(fc));
+ /* Tell device the write index *just past* this latest filled TFD */
q->write_ptr = iwl3945_queue_inc_wrap(q->write_ptr, q->n_bd);
rc = iwl3945_tx_queue_update_write_ptr(priv, txq);
spin_unlock_irqrestore(&priv->lock, flags);
@@ -3329,11 +3425,11 @@ static void iwl3945_txstatus_to_ieee(struct iwl3945_priv *priv,
}
/**
- * iwl3945_tx_queue_reclaim - Reclaim Tx queue entries no more used by NIC.
+ * iwl3945_tx_queue_reclaim - Reclaim Tx queue entries already Tx'd
*
- * When FW advances 'R' index, all entries between old and
- * new 'R' index need to be reclaimed. As result, some free space
- * forms. If there is enough free space (> low mark), wake Tx queue.
+ * When FW advances 'R' index, all entries between old and new 'R' index
+ * need to be reclaimed. As result, some free space forms. If there is
+ * enough free space (> low mark), wake the stack that feeds us.
*/
static int iwl3945_tx_queue_reclaim(struct iwl3945_priv *priv, int txq_id, int index)
{
@@ -3382,6 +3478,9 @@ static int iwl3945_is_tx_success(u32 status)
* Generic RX handler implementations
*
******************************************************************************/
+/**
+ * iwl3945_rx_reply_tx - Handle Tx response
+ */
static void iwl3945_rx_reply_tx(struct iwl3945_priv *priv,
struct iwl3945_rx_mem_buffer *rxb)
{
@@ -3917,6 +4016,7 @@ int iwl3945_rx_queue_update_write_ptr(struct iwl3945_priv *priv, struct iwl3945_
if (q->need_update == 0)
goto exit_unlock;
+ /* If power-saving is in use, make sure device is awake */
if (test_bit(STATUS_POWER_PMI, &priv->status)) {
reg = iwl3945_read32(priv, CSR_UCODE_DRV_GP1);
@@ -3930,10 +4030,14 @@ int iwl3945_rx_queue_update_write_ptr(struct iwl3945_priv *priv, struct iwl3945_
if (rc)
goto exit_unlock;
+ /* Device expects a multiple of 8 */
iwl3945_write_direct32(priv, FH_RSCSR_CHNL0_WPTR,
q->write & ~0x7);
iwl3945_release_nic_access(priv);
+
+ /* Else device is assumed to be awake */
} else
+ /* Device expects a multiple of 8 */
iwl3945_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write & ~0x7);
@@ -3975,9 +4079,12 @@ static int iwl3945_rx_queue_restock(struct iwl3945_priv *priv)
spin_lock_irqsave(&rxq->lock, flags);
write = rxq->write & ~0x7;
while ((iwl3945_rx_queue_space(rxq) > 0) && (rxq->free_count)) {
+ /* Get next free Rx buffer, remove from free list */
element = rxq->rx_free.next;
rxb = list_entry(element, struct iwl3945_rx_mem_buffer, list);
list_del(element);
+
+ /* Point to Rx buffer via next RBD in circular buffer */
rxq->bd[rxq->write] = iwl3945_dma_addr2rbd_ptr(priv, rxb->dma_addr);
rxq->queue[rxq->write] = rxb;
rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
@@ -3990,7 +4097,8 @@ static int iwl3945_rx_queue_restock(struct iwl3945_priv *priv)
queue_work(priv->workqueue, &priv->rx_replenish);
- /* If we've added more space for the firmware to place data, tell it */
+ /* If we've added more space for the firmware to place data, tell it.
+ * Increment device's write pointer in multiples of 8. */
if ((write != (rxq->write & ~0x7))
|| (abs(rxq->write - rxq->read) > 7)) {
spin_lock_irqsave(&rxq->lock, flags);
@@ -4023,6 +4131,8 @@ void iwl3945_rx_replenish(void *data)
while (!list_empty(&rxq->rx_used)) {
element = rxq->rx_used.next;
rxb = list_entry(element, struct iwl3945_rx_mem_buffer, list);
+
+ /* Alloc a new receive buffer */
rxb->skb =
alloc_skb(IWL_RX_BUF_SIZE, __GFP_NOWARN | GFP_ATOMIC);
if (!rxb->skb) {
@@ -4036,6 +4146,8 @@ void iwl3945_rx_replenish(void *data)
}
priv->alloc_rxb_skb++;
list_del(element);
+
+ /* Get physical address of RB/SKB */
rxb->dma_addr =
pci_map_single(priv->pci_dev, rxb->skb->data,
IWL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
@@ -4080,12 +4192,16 @@ int iwl3945_rx_queue_alloc(struct iwl3945_priv *priv)
spin_lock_init(&rxq->lock);
INIT_LIST_HEAD(&rxq->rx_free);
INIT_LIST_HEAD(&rxq->rx_used);
+
+ /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
rxq->bd = pci_alloc_consistent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr);
if (!rxq->bd)
return -ENOMEM;
+
/* Fill the rx_used queue with _all_ of the Rx buffers */
for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
+
/* Set us so that we have processed and used all buffers, but have
* not restocked the Rx queue with fresh buffers */
rxq->read = rxq->write = 0;
@@ -4217,6 +4333,8 @@ static void iwl3945_rx_handle(struct iwl3945_priv *priv)
int reclaim;
unsigned long flags;
+ /* uCode's read index (stored in shared DRAM) indicates the last Rx
+ * buffer that the driver may process (last buffer filled by ucode). */
r = iwl3945_hw_get_rx_read(priv);
i = rxq->read;
@@ -4297,6 +4415,9 @@ static void iwl3945_rx_handle(struct iwl3945_priv *priv)
iwl3945_rx_queue_restock(priv);
}
+/**
+ * iwl3945_tx_queue_update_write_ptr - Send new write index to hardware
+ */
static int iwl3945_tx_queue_update_write_ptr(struct iwl3945_priv *priv,
struct iwl3945_tx_queue *txq)
{
@@ -4924,6 +5045,11 @@ static void iwl3945_init_band_reference(const struct iwl3945_priv *priv, int ban
}
}
+/**
+ * iwl3945_get_channel_info - Find driver's private channel info
+ *
+ * Based on band and channel number.
+ */
const struct iwl3945_channel_info *iwl3945_get_channel_info(const struct iwl3945_priv *priv,
int phymode, u16 channel)
{
@@ -4951,6 +5077,9 @@ const struct iwl3945_channel_info *iwl3945_get_channel_info(const struct iwl3945
#define CHECK_AND_PRINT(x) ((eeprom_ch_info[ch].flags & EEPROM_CHANNEL_##x) \
? # x " " : "")
+/**
+ * iwl3945_init_channel_map - Set up driver's info for all possible channels
+ */
static int iwl3945_init_channel_map(struct iwl3945_priv *priv)
{
int eeprom_ch_count = 0;
@@ -5060,6 +5189,7 @@ static int iwl3945_init_channel_map(struct iwl3945_priv *priv)
}
}
+ /* Set up txpower settings in driver for all channels */
if (iwl3945_txpower_set_from_eeprom(priv))
return -EIO;
@@ -8303,6 +8433,8 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
struct ieee80211_hw *hw;
int i;
+ /* Disabling hardware scan means that mac80211 will perform scans
+ * "the hard way", rather than using device's scan. */
if (iwl3945_param_disable_hw_scan) {
IWL_DEBUG_INFO("Disabling hw_scan\n");
iwl3945_hw_ops.hw_scan = NULL;
@@ -8333,6 +8465,8 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
priv->hw = hw;
priv->pci_dev = pdev;
+
+ /* Select antenna (may be helpful if only one antenna is connected) */
priv->antenna = (enum iwl3945_antenna)iwl3945_param_antenna;
#ifdef CONFIG_IWL3945_DEBUG
iwl3945_debug_level = iwl3945_param_debug;
@@ -8354,6 +8488,7 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
/* Tell mac80211 our Tx characteristics */
hw->flags = IEEE80211_HW_HOST_GEN_BEACON_TEMPLATE;
+ /* 4 EDCA QOS priorities */
hw->queues = 4;
spin_lock_init(&priv->lock);
@@ -8374,6 +8509,7 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
pci_set_master(pdev);
+ /* Clear the driver's (not device's) station table */
iwl3945_clear_stations_table(priv);
priv->data_retry_limit = -1;
@@ -8393,9 +8529,11 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
err = pci_request_regions(pdev, DRV_NAME);
if (err)
goto out_pci_disable_device;
+
/* We disable the RETRY_TIMEOUT register (0x41) to keep
* PCI Tx retries from interfering with C3 CPU state */
pci_write_config_byte(pdev, 0x41, 0x00);
+
priv->hw_base = pci_iomap(pdev, 0, 0);
if (!priv->hw_base) {
err = -ENODEV;
@@ -8408,6 +8546,7 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
/* Initialize module parameter values here */
+ /* Disable radio (SW RF KILL) via parameter when loading driver */
if (iwl3945_param_disable) {
set_bit(STATUS_RF_KILL_SW, &priv->status);
IWL_DEBUG_INFO("Radio disabled.\n");
diff --git a/drivers/net/wireless/iwlwifi/iwl4965-base.c b/drivers/net/wireless/iwlwifi/iwl4965-base.c
index 03c3af8..ddeedf6 100644
--- a/drivers/net/wireless/iwlwifi/iwl4965-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl4965-base.c
@@ -63,13 +63,13 @@ static int iwl4965_tx_queue_update_write_ptr(struct iwl4965_priv *priv,
******************************************************************************/
/* module parameters */
-static int iwl4965_param_disable_hw_scan;
-static int iwl4965_param_debug;
+static int iwl4965_param_disable_hw_scan; /* def: 0 = use 4965's h/w scan */
+static int iwl4965_param_debug; /* def: 0 = minimal debug log messages */
static int iwl4965_param_disable; /* def: enable radio */
static int iwl4965_param_antenna; /* def: 0 = both antennas (use diversity) */
int iwl4965_param_hwcrypto; /* def: using software encryption */
-static int iwl4965_param_qos_enable = 1;
-int iwl4965_param_queues_num = IWL_MAX_NUM_QUEUES;
+static int iwl4965_param_qos_enable = 1; /* def: 1 = use quality of service */
+int iwl4965_param_queues_num = IWL_MAX_NUM_QUEUES; /* def: 16 Tx queues */
int iwl4965_param_amsdu_size_8K; /* def: enable 8K amsdu size */
/*
@@ -184,17 +184,24 @@ static void iwl4965_print_hex_dump(int level, void *p, u32 len)
*
* Theory of operation
*
- * A queue is a circular buffers with 'Read' and 'Write' pointers.
- * 2 empty entries always kept in the buffer to protect from overflow.
+ * A Tx or Rx queue resides in host DRAM, and is comprised of a circular buffer
+ * of buffer descriptors, each of which points to one or more data buffers for
+ * the device to read from or fill. Driver and device exchange status of each
+ * queue via "read" and "write" pointers. Driver keeps minimum of 2 empty
+ * entries in each circular buffer, to protect against confusing empty and full
+ * queue states.
+ *
+ * The device reads or writes the data in the queues via the device's several
+ * DMA/FIFO channels. Each queue is mapped to a single DMA channel.
*
* For Tx queue, there are low mark and high mark limits. If, after queuing
* the packet for Tx, free space become < low mark, Tx queue stopped. When
* reclaiming packets (on 'tx done IRQ), if free space become > high mark,
* Tx queue resumed.
*
- * The IWL operates with six queues, one receive queue in the device's
- * sram, one transmit queue for sending commands to the device firmware,
- * and four transmit queues for data.
+ * The 4965 operates with up to 17 queues: One receive queue, one transmit
+ * queue (#4) for sending commands to the device firmware, and 15 other
+ * Tx queues that may be mapped to prioritized Tx DMA/FIFO channels.
***************************************************/
static int iwl4965_queue_space(const struct iwl4965_queue *q)
@@ -213,13 +220,21 @@ static int iwl4965_queue_space(const struct iwl4965_queue *q)
return s;
}
-/* XXX: n_bd must be power-of-two size */
+/**
+ * iwl4965_queue_inc_wrap - increment queue index, wrap back to beginning
+ * @index -- current index
+ * @n_bd -- total number of entries in queue (must be power of 2)
+ */
static inline int iwl4965_queue_inc_wrap(int index, int n_bd)
{
return ++index & (n_bd - 1);
}
-/* XXX: n_bd must be power-of-two size */
+/**
+ * iwl4965_queue_dec_wrap - decrement queue index, wrap back to end
+ * @index -- current index
+ * @n_bd -- total number of entries in queue (must be power of 2)
+ */
static inline int iwl4965_queue_dec_wrap(int index, int n_bd)
{
return --index & (n_bd - 1);
@@ -234,12 +249,17 @@ static inline int x2_queue_used(const struct iwl4965_queue *q, int i)
static inline u8 get_cmd_index(struct iwl4965_queue *q, u32 index, int is_huge)
{
+ /* This is for scan command, the big buffer at end of command array */
if (is_huge)
- return q->n_window;
+ return q->n_window; /* must be power of 2 */
+ /* Otherwise, use normal size buffers */
return index & (q->n_window - 1);
}
+/**
+ * iwl4965_queue_init - Initialize queue's high/low-water and read/write indexes
+ */
static int iwl4965_queue_init(struct iwl4965_priv *priv, struct iwl4965_queue *q,
int count, int slots_num, u32 id)
{
@@ -268,11 +288,16 @@ static int iwl4965_queue_init(struct iwl4965_priv *priv, struct iwl4965_queue *q
return 0;
}
+/**
+ * iwl4965_tx_queue_alloc - Alloc driver data and TFD CB for one Tx/cmd queue
+ */
static int iwl4965_tx_queue_alloc(struct iwl4965_priv *priv,
struct iwl4965_tx_queue *txq, u32 id)
{
struct pci_dev *dev = priv->pci_dev;
+ /* Driver private data, only for Tx (not command) queues,
+ * not shared with device. */
if (id != IWL_CMD_QUEUE_NUM) {
txq->txb = kmalloc(sizeof(txq->txb[0]) *
TFD_QUEUE_SIZE_MAX, GFP_KERNEL);
@@ -284,6 +309,8 @@ static int iwl4965_tx_queue_alloc(struct iwl4965_priv *priv,
} else
txq->txb = NULL;
+ /* Circular buffer of transmit frame descriptors (TFDs),
+ * shared with device */
txq->bd = pci_alloc_consistent(dev,
sizeof(txq->bd[0]) * TFD_QUEUE_SIZE_MAX,
&txq->q.dma_addr);
@@ -358,8 +385,8 @@ int iwl4965_tx_queue_init(struct iwl4965_priv *priv,
* @txq: Transmit queue to deallocate.
*
* Empty queue by removing and destroying all BD's.
- * Free all buffers. txq itself is not freed.
- *
+ * Free all buffers.
+ * 0-fill, but do not free "txq" descriptor structure.
*/
void iwl4965_tx_queue_free(struct iwl4965_priv *priv, struct iwl4965_tx_queue *txq)
{
@@ -379,19 +406,21 @@ void iwl4965_tx_queue_free(struct iwl4965_priv *priv, struct iwl4965_tx_queue *t
if (q->id == IWL_CMD_QUEUE_NUM)
len += IWL_MAX_SCAN_SIZE;
+ /* De-alloc array of command/tx buffers */
pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd);
- /* free buffers belonging to queue itself */
+ /* De-alloc circular buffer of TFDs */
if (txq->q.n_bd)
pci_free_consistent(dev, sizeof(struct iwl4965_tfd_frame) *
txq->q.n_bd, txq->bd, txq->q.dma_addr);
+ /* De-alloc array of per-TFD driver data */
if (txq->txb) {
kfree(txq->txb);
txq->txb = NULL;
}
- /* 0 fill whole structure */
+ /* 0-fill queue descriptor structure */
memset(txq, 0, sizeof(*txq));
}
@@ -405,6 +434,11 @@ const u8 iwl4965_broadcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
/**************************************************************/
#if 0 /* temporary disable till we add real remove station */
+/**
+ * iwl4965_remove_station - Remove driver's knowledge of station.
+ *
+ * NOTE: This does not remove station from device's station table.
+ */
static u8 iwl4965_remove_station(struct iwl4965_priv *priv, const u8 *addr, int is_ap)
{
int index = IWL_INVALID_STATION;
@@ -442,6 +476,11 @@ out:
}
#endif
+/**
+ * iwl4965_clear_stations_table - Clear the driver's station table
+ *
+ * NOTE: This does not clear or otherwise alter the device's station table.
+ */
static void iwl4965_clear_stations_table(struct iwl4965_priv *priv)
{
unsigned long flags;
@@ -454,6 +493,9 @@ static void iwl4965_clear_stations_table(struct iwl4965_priv *priv)
spin_unlock_irqrestore(&priv->sta_lock, flags);
}
+/**
+ * iwl4965_add_station_flags - Add station to tables in driver and device
+ */
u8 iwl4965_add_station_flags(struct iwl4965_priv *priv, const u8 *addr,
int is_ap, u8 flags, void *ht_data)
{
@@ -501,6 +543,7 @@ u8 iwl4965_add_station_flags(struct iwl4965_priv *priv, const u8 *addr,
station->used = 1;
priv->num_stations++;
+ /* Set up the REPLY_ADD_STA command to send to device */
memset(&station->sta, 0, sizeof(struct iwl4965_addsta_cmd));
memcpy(station->sta.sta.addr, addr, ETH_ALEN);
station->sta.mode = 0;
@@ -516,6 +559,8 @@ u8 iwl4965_add_station_flags(struct iwl4965_priv *priv, const u8 *addr,
#endif /*CONFIG_IWL4965_HT*/
spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
+
+ /* Add station to device's station table */
iwl4965_send_add_station(priv, &station->sta, flags);
return index;
@@ -685,7 +730,11 @@ static int iwl4965_enqueue_hcmd(struct iwl4965_priv *priv, struct iwl4965_host_c
fix_size, q->write_ptr, idx, IWL_CMD_QUEUE_NUM);
txq->need_update = 1;
+
+ /* Set up entry in queue's byte count circular buffer */
ret = iwl4965_tx_queue_update_wr_ptr(priv, txq, 0);
+
+ /* Increment and update queue's write index */
q->write_ptr = iwl4965_queue_inc_wrap(q->write_ptr, q->n_bd);
iwl4965_tx_queue_update_write_ptr(priv, txq);
@@ -862,9 +911,11 @@ static int iwl4965_rxon_add_station(struct iwl4965_priv *priv,
0, cur_ht_config);
else
#endif /* CONFIG_IWL4965_HT */
+ /* Add station to device's station table */
sta_id = iwl4965_add_station_flags(priv, addr, is_ap,
0, NULL);
+ /* Set up default rate scaling table in device's station table */
iwl4965_add_station(priv, addr, is_ap);
return sta_id;
@@ -1590,7 +1641,7 @@ static void get_eeprom_mac(struct iwl4965_priv *priv, u8 *mac)
/**
* iwl4965_eeprom_init - read EEPROM contents
*
- * Load the EEPROM from adapter into priv->eeprom
+ * Load the EEPROM contents from adapter into priv->eeprom
*
* NOTE: This routine uses the non-debug IO access functions.
*/
@@ -1615,6 +1666,7 @@ int iwl4965_eeprom_init(struct iwl4965_priv *priv)
return -ENOENT;
}
+ /* Make sure driver (instead of uCode) is allowed to read EEPROM */
rc = iwl4965_eeprom_acquire_semaphore(priv);
if (rc < 0) {
IWL_ERROR("Failed to acquire EEPROM semaphore.\n");
@@ -2755,6 +2807,11 @@ static void iwl4965_build_tx_cmd_basic(struct iwl4965_priv *priv,
cmd->cmd.tx.next_frame_len = 0;
}
+/**
+ * iwl4965_get_sta_id - Find station's index within station table
+ *
+ * If new IBSS station, create new entry in station table
+ */
static int iwl4965_get_sta_id(struct iwl4965_priv *priv,
struct ieee80211_hdr *hdr)
{
@@ -2762,16 +2819,15 @@ static int iwl4965_get_sta_id(struct iwl4965_priv *priv,
u16 fc = le16_to_cpu(hdr->frame_control);
DECLARE_MAC_BUF(mac);
- /* If this frame is broadcast or not data then use the broadcast
- * station id */
+ /* If this frame is broadcast or management, use broadcast station id */
if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) ||
is_multicast_ether_addr(hdr->addr1))
return priv->hw_setting.bcast_sta_id;
switch (priv->iw_mode) {
- /* If this frame is part of a BSS network (we're a station), then
- * we use the AP's station id */
+ /* If we are a client station in a BSS network, use the special
+ * AP station entry (that's the only station we communicate with) */
case IEEE80211_IF_TYPE_STA:
return IWL_AP_ID;
@@ -2782,13 +2838,14 @@ static int iwl4965_get_sta_id(struct iwl4965_priv *priv,
return sta_id;
return priv->hw_setting.bcast_sta_id;
- /* If this frame is part of a IBSS network, then we use the
- * target specific station id */
+ /* If this frame is going out to an IBSS network, find the station,
+ * or create a new station table entry */
case IEEE80211_IF_TYPE_IBSS:
sta_id = iwl4965_hw_find_station(priv, hdr->addr1);
if (sta_id != IWL_INVALID_STATION)
return sta_id;
+ /* Create new station table entry */
sta_id = iwl4965_add_station_flags(priv, hdr->addr1,
0, CMD_ASYNC, NULL);
@@ -2871,6 +2928,8 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv,
spin_unlock_irqrestore(&priv->lock, flags);
hdr_len = ieee80211_get_hdrlen(fc);
+
+ /* Find (or create) index into station table for destination station */
sta_id = iwl4965_get_sta_id(priv, hdr);
if (sta_id == IWL_INVALID_STATION) {
DECLARE_MAC_BUF(mac);
@@ -2899,30 +2958,52 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv,
#endif /* CONFIG_IWL4965_HT_AGG */
#endif /* CONFIG_IWL4965_HT */
}
+
+ /* Descriptor for chosen Tx queue */
txq = &priv->txq[txq_id];
q = &txq->q;
spin_lock_irqsave(&priv->lock, flags);
+ /* Set up first empty TFD within this queue's circular TFD buffer */
tfd = &txq->bd[q->write_ptr];
memset(tfd, 0, sizeof(*tfd));
control_flags = (u32 *) tfd;
idx = get_cmd_index(q, q->write_ptr, 0);
+ /* Set up driver data for this TFD */
memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl4965_tx_info));
txq->txb[q->write_ptr].skb[0] = skb;
memcpy(&(txq->txb[q->write_ptr].status.control),
ctl, sizeof(struct ieee80211_tx_control));
+
+ /* Set up first empty entry in queue's array of Tx/cmd buffers */
out_cmd = &txq->cmd[idx];
memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr));
memset(&out_cmd->cmd.tx, 0, sizeof(out_cmd->cmd.tx));
+
+ /*
+ * Set up the Tx-command (not MAC!) header.
+ * Store the chosen Tx queue and TFD index within the sequence field;
+ * after Tx, uCode's Tx response will return this value so driver can
+ * locate the frame within the tx queue and do post-tx processing.
+ */
out_cmd->hdr.cmd = REPLY_TX;
out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) |
INDEX_TO_SEQ(q->write_ptr)));
- /* copy frags header */
+
+ /* Copy MAC header from skb into command buffer */
memcpy(out_cmd->cmd.tx.hdr, hdr, hdr_len);
- /* hdr = (struct ieee80211_hdr *)out_cmd->cmd.tx.hdr; */
+ /*
+ * Use the first empty entry in this queue's command buffer array
+ * to contain the Tx command and MAC header concatenated together
+ * (payload data will be in another buffer).
+ * Size of this varies, due to varying MAC header length.
+ * If end is not dword aligned, we'll have 2 extra bytes at the end
+ * of the MAC header (device reads on dword boundaries).
+ * We'll tell device about this padding later.
+ */
len = priv->hw_setting.tx_cmd_len +
sizeof(struct iwl4965_cmd_header) + hdr_len;
@@ -2934,15 +3015,20 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv,
else
len_org = 0;
+ /* Physical address of this Tx command's header (not MAC header!),
+ * within command buffer array. */
txcmd_phys = txq->dma_addr_cmd + sizeof(struct iwl4965_cmd) * idx +
offsetof(struct iwl4965_cmd, hdr);
+ /* Add buffer containing Tx command and MAC(!) header to TFD's
+ * first entry */
iwl4965_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len);
if (!(ctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
iwl4965_build_tx_cmd_hwcrypto(priv, ctl, out_cmd, skb, 0);
- /* 802.11 null functions have no payload... */
+ /* Set up TFD's 2nd entry to point directly to remainder of skb,
+ * if any (802.11 null frames have no payload). */
len = skb->len - hdr_len;
if (len) {
phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len,
@@ -2950,9 +3036,11 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv,
iwl4965_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, len);
}
+ /* Tell 4965 about any 2-byte padding after MAC header */
if (len_org)
out_cmd->cmd.tx.tx_flags |= TX_CMD_FLG_MH_PAD_MSK;
+ /* Total # bytes to be transmitted */
len = (u16)skb->len;
out_cmd->cmd.tx.len = cpu_to_le16(len);
@@ -2982,8 +3070,10 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv,
iwl4965_print_hex_dump(IWL_DL_TX, (u8 *)out_cmd->cmd.tx.hdr,
ieee80211_get_hdrlen(fc));
+ /* Set up entry for this TFD in Tx byte-count array */
iwl4965_tx_queue_update_wr_ptr(priv, txq, len);
+ /* Tell device the write index *just past* this latest filled TFD */
q->write_ptr = iwl4965_queue_inc_wrap(q->write_ptr, q->n_bd);
rc = iwl4965_tx_queue_update_write_ptr(priv, txq);
spin_unlock_irqrestore(&priv->lock, flags);
@@ -3460,11 +3550,11 @@ static void iwl4965_txstatus_to_ieee(struct iwl4965_priv *priv,
}
/**
- * iwl4965_tx_queue_reclaim - Reclaim Tx queue entries no more used by NIC.
+ * iwl4965_tx_queue_reclaim - Reclaim Tx queue entries already Tx'd
*
- * When FW advances 'R' index, all entries between old and
- * new 'R' index need to be reclaimed. As result, some free space
- * forms. If there is enough free space (> low mark), wake Tx queue.
+ * When FW advances 'R' index, all entries between old and new 'R' index
+ * need to be reclaimed. As result, some free space forms. If there is
+ * enough free space (> low mark), wake the stack that feeds us.
*/
int iwl4965_tx_queue_reclaim(struct iwl4965_priv *priv, int txq_id, int index)
{
@@ -3545,6 +3635,10 @@ static inline u32 iwl4965_get_scd_ssn(struct iwl4965_tx_resp *tx_resp)
return le32_to_cpu(*scd_ssn) & MAX_SN;
}
+
+/**
+ * iwl4965_tx_status_reply_tx - Handle Tx rspnse for frames in aggregation queue
+ */
static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv,
struct iwl4965_ht_agg *agg,
struct iwl4965_tx_resp *tx_resp,
@@ -3559,14 +3653,16 @@ static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv,
u16 seq;
if (agg->wait_for_ba)
- IWL_DEBUG_TX_REPLY("got tx repsons w/o back\n");
+ IWL_DEBUG_TX_REPLY("got tx response w/o block-ack\n");
agg->frame_count = tx_resp->frame_count;
agg->start_idx = start_idx;
agg->rate_n_flags = le32_to_cpu(tx_resp->rate_n_flags);
agg->bitmap0 = agg->bitmap1 = 0;
+ /* # frames attempted by Tx command */
if (agg->frame_count == 1) {
+ /* Only one frame was attempted; no block-ack will arrive */
struct iwl4965_tx_queue *txq ;
status = le32_to_cpu(frame_status[0]);
@@ -3595,9 +3691,11 @@ static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv,
agg->wait_for_ba = 0;
} else {
+ /* Two or more frames were attempted; expect block-ack */
u64 bitmap = 0;
int start = agg->start_idx;
+ /* Construct bit-map of pending frames within Tx window */
for (i = 0; i < agg->frame_count; i++) {
u16 sc;
status = le32_to_cpu(frame_status[i]);
@@ -3661,6 +3759,9 @@ static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv,
#endif
#endif
+/**
+ * iwl4965_rx_reply_tx - Handle standard (non-aggregation) Tx response
+ */
static void iwl4965_rx_reply_tx(struct iwl4965_priv *priv,
struct iwl4965_rx_mem_buffer *rxb)
{
@@ -4282,6 +4383,7 @@ int iwl4965_rx_queue_update_write_ptr(struct iwl4965_priv *priv, struct iwl4965_
if (q->need_update == 0)
goto exit_unlock;
+ /* If power-saving is in use, make sure device is awake */
if (test_bit(STATUS_POWER_PMI, &priv->status)) {
reg = iwl4965_read32(priv, CSR_UCODE_DRV_GP1);
@@ -4295,10 +4397,14 @@ int iwl4965_rx_queue_update_write_ptr(struct iwl4965_priv *priv, struct iwl4965_
if (rc)
goto exit_unlock;
+ /* Device expects a multiple of 8 */
iwl4965_write_direct32(priv, FH_RSCSR_CHNL0_WPTR,
q->write & ~0x7);
iwl4965_release_nic_access(priv);
+
+ /* Else device is assumed to be awake */
} else
+ /* Device expects a multiple of 8 */
iwl4965_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write & ~0x7);
@@ -4341,9 +4447,12 @@ static int iwl4965_rx_queue_restock(struct iwl4965_priv *priv)
spin_lock_irqsave(&rxq->lock, flags);
write = rxq->write & ~0x7;
while ((iwl4965_rx_queue_space(rxq) > 0) && (rxq->free_count)) {
+ /* Get next free Rx buffer, remove from free list */
element = rxq->rx_free.next;
rxb = list_entry(element, struct iwl4965_rx_mem_buffer, list);
list_del(element);
+
+ /* Point to Rx buffer via next RBD in circular buffer */
rxq->bd[rxq->write] = iwl4965_dma_addr2rbd_ptr(priv, rxb->dma_addr);
rxq->queue[rxq->write] = rxb;
rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
@@ -4356,7 +4465,8 @@ static int iwl4965_rx_queue_restock(struct iwl4965_priv *priv)
queue_work(priv->workqueue, &priv->rx_replenish);
- /* If we've added more space for the firmware to place data, tell it */
+ /* If we've added more space for the firmware to place data, tell it.
+ * Increment device's write pointer in multiples of 8. */
if ((write != (rxq->write & ~0x7))
|| (abs(rxq->write - rxq->read) > 7)) {
spin_lock_irqsave(&rxq->lock, flags);
@@ -4389,6 +4499,8 @@ void iwl4965_rx_replenish(void *data)
while (!list_empty(&rxq->rx_used)) {
element = rxq->rx_used.next;
rxb = list_entry(element, struct iwl4965_rx_mem_buffer, list);
+
+ /* Alloc a new receive buffer */
rxb->skb =
alloc_skb(priv->hw_setting.rx_buf_size,
__GFP_NOWARN | GFP_ATOMIC);
@@ -4403,6 +4515,8 @@ void iwl4965_rx_replenish(void *data)
}
priv->alloc_rxb_skb++;
list_del(element);
+
+ /* Get physical address of RB/SKB */
rxb->dma_addr =
pci_map_single(priv->pci_dev, rxb->skb->data,
priv->hw_setting.rx_buf_size, PCI_DMA_FROMDEVICE);
@@ -4448,12 +4562,16 @@ int iwl4965_rx_queue_alloc(struct iwl4965_priv *priv)
spin_lock_init(&rxq->lock);
INIT_LIST_HEAD(&rxq->rx_free);
INIT_LIST_HEAD(&rxq->rx_used);
+
+ /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
rxq->bd = pci_alloc_consistent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr);
if (!rxq->bd)
return -ENOMEM;
+
/* Fill the rx_used queue with _all_ of the Rx buffers */
for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
+
/* Set us so that we have processed and used all buffers, but have
* not restocked the Rx queue with fresh buffers */
rxq->read = rxq->write = 0;
@@ -4586,6 +4704,8 @@ static void iwl4965_rx_handle(struct iwl4965_priv *priv)
int reclaim;
unsigned long flags;
+ /* uCode's read index (stored in shared DRAM) indicates the last Rx
+ * buffer that the driver may process (last buffer filled by ucode). */
r = iwl4965_hw_get_rx_read(priv);
i = rxq->read;
@@ -4670,6 +4790,9 @@ static void iwl4965_rx_handle(struct iwl4965_priv *priv)
iwl4965_rx_queue_restock(priv);
}
+/**
+ * iwl4965_tx_queue_update_write_ptr - Send new write index to hardware
+ */
static int iwl4965_tx_queue_update_write_ptr(struct iwl4965_priv *priv,
struct iwl4965_tx_queue *txq)
{
@@ -5301,6 +5424,11 @@ static void iwl4965_init_band_reference(const struct iwl4965_priv *priv,
}
}
+/**
+ * iwl4965_get_channel_info - Find driver's private channel info
+ *
+ * Based on band and channel number.
+ */
const struct iwl4965_channel_info *iwl4965_get_channel_info(const struct iwl4965_priv *priv,
int phymode, u16 channel)
{
@@ -5328,6 +5456,9 @@ const struct iwl4965_channel_info *iwl4965_get_channel_info(const struct iwl4965
#define CHECK_AND_PRINT(x) ((eeprom_ch_info[ch].flags & EEPROM_CHANNEL_##x) \
? # x " " : "")
+/**
+ * iwl4965_init_channel_map - Set up driver's info for all possible channels
+ */
static int iwl4965_init_channel_map(struct iwl4965_priv *priv)
{
int eeprom_ch_count = 0;
@@ -5437,6 +5568,7 @@ static int iwl4965_init_channel_map(struct iwl4965_priv *priv)
}
}
+ /* Two additional EEPROM bands for 2.4 and 5 GHz FAT channels */
for (band = 6; band <= 7; band++) {
int phymode;
u8 fat_extension_chan;
@@ -5444,7 +5576,9 @@ static int iwl4965_init_channel_map(struct iwl4965_priv *priv)
iwl4965_init_band_reference(priv, band, &eeprom_ch_count,
&eeprom_ch_info, &eeprom_ch_index);
+ /* EEPROM band 6 is 2.4, band 7 is 5 GHz */
phymode = (band == 6) ? MODE_IEEE80211B : MODE_IEEE80211A;
+
/* Loop through each band adding each of the channels */
for (ch = 0; ch < eeprom_ch_count; ch++) {
@@ -5456,11 +5590,13 @@ static int iwl4965_init_channel_map(struct iwl4965_priv *priv)
else
fat_extension_chan = HT_IE_EXT_CHANNEL_ABOVE;
+ /* Set up driver's info for lower half */
iwl4965_set_fat_chan_info(priv, phymode,
eeprom_ch_index[ch],
&(eeprom_ch_info[ch]),
fat_extension_chan);
+ /* Set up driver's info for upper half */
iwl4965_set_fat_chan_info(priv, phymode,
(eeprom_ch_index[ch] + 4),
&(eeprom_ch_info[ch]),
@@ -8874,6 +9010,8 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
struct ieee80211_hw *hw;
int i;
+ /* Disabling hardware scan means that mac80211 will perform scans
+ * "the hard way", rather than using device's scan. */
if (iwl4965_param_disable_hw_scan) {
IWL_DEBUG_INFO("Disabling hw_scan\n");
iwl4965_hw_ops.hw_scan = NULL;
@@ -8925,9 +9063,11 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
/* Tell mac80211 our Tx characteristics */
hw->flags = IEEE80211_HW_HOST_GEN_BEACON_TEMPLATE;
+ /* Default value; 4 EDCA QOS priorities */
hw->queues = 4;
#ifdef CONFIG_IWL4965_HT
#ifdef CONFIG_IWL4965_HT_AGG
+ /* Enhanced value; more queues, to support 11n aggregation */
hw->queues = 16;
#endif /* CONFIG_IWL4965_HT_AGG */
#endif /* CONFIG_IWL4965_HT */
@@ -8951,6 +9091,7 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
pci_set_master(pdev);
+ /* Clear the driver's (not device's) station table */
iwl4965_clear_stations_table(priv);
priv->data_retry_limit = -1;
@@ -8970,9 +9111,11 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
err = pci_request_regions(pdev, DRV_NAME);
if (err)
goto out_pci_disable_device;
+
/* We disable the RETRY_TIMEOUT register (0x41) to keep
* PCI Tx retries from interfering with C3 CPU state */
pci_write_config_byte(pdev, 0x41, 0x00);
+
priv->hw_base = pci_iomap(pdev, 0, 0);
if (!priv->hw_base) {
err = -ENODEV;
@@ -8985,6 +9128,7 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
/* Initialize module parameter values here */
+ /* Disable radio (SW RF KILL) via parameter when loading driver */
if (iwl4965_param_disable) {
set_bit(STATUS_RF_KILL_SW, &priv->status);
IWL_DEBUG_INFO("Radio disabled.\n");
@@ -8997,6 +9141,7 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
priv->valid_antenna = 0x7; /* assume all 3 connected */
priv->ps_mode = IWL_MIMO_PS_NONE;
+ /* Choose which receivers/antennas to use */
iwl4965_set_rxon_chain(priv);
printk(KERN_INFO DRV_NAME
--
1.5.2.2
---------------------------------------------------------------------
Intel Israel (74) Limited
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