From: Ulrich Kunitz <kune@xxxxxxxxxxxxxx>
As pointed out by Daniel Drake, the zd1211rw driver used several
different rate values and names throughout the driver. He has
written a patch to change it and tweaked it after some pretty wild
ideas from my side. But the discussion helped me to understand the
problem better and I think I have nailed it down with this patch.
A zd-rate will consist from now on of a four-bit "pure" rate value
and a modulation type flag as used in the ZD1211 control set used
for packet transmission. This is consistent with the usage in the
zd_rates table. If possible these zd-rates should be used in the
code.
Signed-off-by: Ulrich Kunitz <kune@xxxxxxxxxxxxxx>
Signed-off-by: Daniel Drake <dsd@xxxxxxxxxx>
---
zd_chip.c | 51 ++++++++++++++++-------------
zd_ieee80211.h | 43 +++++++++++++++---------
zd_mac.c | 99 +++++++++++++++----------------------------------------
zd_mac.h | 65 +++++++++++++++++++++++++------------
4 files changed, 126 insertions(+), 132 deletions(-)
Index: linux/drivers/net/wireless/zd1211rw/zd_chip.c
===================================================================
--- linux.orig/drivers/net/wireless/zd1211rw/zd_chip.c
+++ linux/drivers/net/wireless/zd1211rw/zd_chip.c
@@ -1009,19 +1009,19 @@ int zd_chip_set_rts_cts_rate_locked(stru
u32 value = 0;
/* Modulation bit */
- if (ZD_CS_TYPE(rts_rate) == ZD_CS_OFDM)
+ if (ZD_MODULATION_TYPE(rts_rate) == ZD_OFDM)
rts_mod = ZD_RX_OFDM;
dev_dbg_f(zd_chip_dev(chip), "rts_rate=%x preamble=%x\n",
rts_rate, preamble);
- value |= rts_rate << RTSCTS_SH_RTS_RATE;
+ value |= ZD_PURE_RATE(rts_rate) << RTSCTS_SH_RTS_RATE;
value |= rts_mod << RTSCTS_SH_RTS_MOD_TYPE;
value |= preamble << RTSCTS_SH_RTS_PMB_TYPE;
value |= preamble << RTSCTS_SH_CTS_PMB_TYPE;
/* We always send 11M self-CTS messages, like the vendor driver. */
- value |= ZD_CCK_RATE_11M << RTSCTS_SH_CTS_RATE;
+ value |= ZD_PURE_RATE(ZD_CCK_RATE_11M) << RTSCTS_SH_CTS_RATE;
value |= ZD_RX_CCK << RTSCTS_SH_CTS_MOD_TYPE;
return zd_iowrite32_locked(chip, value, CR_RTS_CTS_RATE);
@@ -1328,7 +1328,7 @@ int zd_chip_set_basic_rates_locked(struc
return zd_iowrite32_locked(chip, cr_rates, CR_BASIC_RATE_TBL);
}
-static int ofdm_qual_db(u8 status_quality, u8 rate, unsigned int size)
+static int ofdm_qual_db(u8 status_quality, u8 zd_rate, unsigned int size)
{
static const u16 constants[] = {
715, 655, 585, 540, 470, 410, 360, 315,
@@ -1342,7 +1342,7 @@ static int ofdm_qual_db(u8 status_qualit
/* It seems that their quality parameter is somehow per signal
* and is now transferred per bit.
*/
- switch (rate) {
+ switch (zd_rate) {
case ZD_OFDM_RATE_6M:
case ZD_OFDM_RATE_12M:
case ZD_OFDM_RATE_24M:
@@ -1369,7 +1369,7 @@ static int ofdm_qual_db(u8 status_qualit
break;
}
- switch (rate) {
+ switch (zd_rate) {
case ZD_OFDM_RATE_6M:
case ZD_OFDM_RATE_9M:
i += 3;
@@ -1393,11 +1393,11 @@ static int ofdm_qual_db(u8 status_qualit
return i;
}
-static int ofdm_qual_percent(u8 status_quality, u8 rate, unsigned int size)
+static int ofdm_qual_percent(u8 status_quality, u8 zd_rate, unsigned int size)
{
int r;
- r = ofdm_qual_db(status_quality, rate, size);
+ r = ofdm_qual_db(status_quality, zd_rate, size);
ZD_ASSERT(r >= 0);
if (r < 0)
r = 0;
@@ -1458,12 +1458,17 @@ static int cck_qual_percent(u8 status_qu
return r <= 100 ? r : 100;
}
+static inline u8 zd_rate_from_ofdm_plcp_header(const void *rx_frame)
+{
+ return ZD_OFDM | zd_ofdm_plcp_header_rate(rx_frame);
+}
+
u8 zd_rx_qual_percent(const void *rx_frame, unsigned int size,
const struct rx_status *status)
{
return (status->frame_status&ZD_RX_OFDM) ?
ofdm_qual_percent(status->signal_quality_ofdm,
- zd_ofdm_plcp_header_rate(rx_frame),
+ zd_rate_from_ofdm_plcp_header(rx_frame),
size) :
cck_qual_percent(status->signal_quality_cck);
}
@@ -1479,32 +1484,32 @@ u8 zd_rx_strength_percent(u8 rssi)
u16 zd_rx_rate(const void *rx_frame, const struct rx_status *status)
{
static const u16 ofdm_rates[] = {
- [ZD_OFDM_RATE_6M] = 60,
- [ZD_OFDM_RATE_9M] = 90,
- [ZD_OFDM_RATE_12M] = 120,
- [ZD_OFDM_RATE_18M] = 180,
- [ZD_OFDM_RATE_24M] = 240,
- [ZD_OFDM_RATE_36M] = 360,
- [ZD_OFDM_RATE_48M] = 480,
- [ZD_OFDM_RATE_54M] = 540,
+ [ZD_OFDM_PLCP_RATE_6M] = 60,
+ [ZD_OFDM_PLCP_RATE_9M] = 90,
+ [ZD_OFDM_PLCP_RATE_12M] = 120,
+ [ZD_OFDM_PLCP_RATE_18M] = 180,
+ [ZD_OFDM_PLCP_RATE_24M] = 240,
+ [ZD_OFDM_PLCP_RATE_36M] = 360,
+ [ZD_OFDM_PLCP_RATE_48M] = 480,
+ [ZD_OFDM_PLCP_RATE_54M] = 540,
};
u16 rate;
if (status->frame_status & ZD_RX_OFDM) {
+ /* Deals with PLCP OFDM rate (not zd_rates) */
u8 ofdm_rate = zd_ofdm_plcp_header_rate(rx_frame);
rate = ofdm_rates[ofdm_rate & 0xf];
} else {
- u8 cck_rate = zd_cck_plcp_header_rate(rx_frame);
- switch (cck_rate) {
- case ZD_CCK_SIGNAL_1M:
+ switch (zd_cck_plcp_header_signal(rx_frame)) {
+ case ZD_CCK_PLCP_SIGNAL_1M:
rate = 10;
break;
- case ZD_CCK_SIGNAL_2M:
+ case ZD_CCK_PLCP_SIGNAL_2M:
rate = 20;
break;
- case ZD_CCK_SIGNAL_5M5:
+ case ZD_CCK_PLCP_SIGNAL_5M5:
rate = 55;
break;
- case ZD_CCK_SIGNAL_11M:
+ case ZD_CCK_PLCP_SIGNAL_11M:
rate = 110;
break;
default:
Index: linux/drivers/net/wireless/zd1211rw/zd_ieee80211.h
===================================================================
--- linux.orig/drivers/net/wireless/zd1211rw/zd_ieee80211.h
+++ linux/drivers/net/wireless/zd1211rw/zd_ieee80211.h
@@ -43,21 +43,25 @@ struct ofdm_plcp_header {
__le16 service;
} __attribute__((packed));
-static inline u8 zd_ofdm_plcp_header_rate(
- const struct ofdm_plcp_header *header)
+static inline u8 zd_ofdm_plcp_header_rate(const struct ofdm_plcp_header *header)
{
return header->prefix[0] & 0xf;
}
-/* These are referred to as zd_rates */
-#define ZD_OFDM_RATE_6M 0xb
-#define ZD_OFDM_RATE_9M 0xf
-#define ZD_OFDM_RATE_12M 0xa
-#define ZD_OFDM_RATE_18M 0xe
-#define ZD_OFDM_RATE_24M 0x9
-#define ZD_OFDM_RATE_36M 0xd
-#define ZD_OFDM_RATE_48M 0x8
-#define ZD_OFDM_RATE_54M 0xc
+/* The following defines give the encoding of the 4-bit rate field in the
+ * OFDM (802.11a/802.11g) PLCP header. Notify that these values are used to
+ * define the zd-rate values for OFDM.
+ *
+ * See the struct zd_ctrlset definition in zd_mac.h.
+ */
+#define ZD_OFDM_PLCP_RATE_6M 0xb
+#define ZD_OFDM_PLCP_RATE_9M 0xf
+#define ZD_OFDM_PLCP_RATE_12M 0xa
+#define ZD_OFDM_PLCP_RATE_18M 0xe
+#define ZD_OFDM_PLCP_RATE_24M 0x9
+#define ZD_OFDM_PLCP_RATE_36M 0xd
+#define ZD_OFDM_PLCP_RATE_48M 0x8
+#define ZD_OFDM_PLCP_RATE_54M 0xc
struct cck_plcp_header {
u8 signal;
@@ -66,15 +70,22 @@ struct cck_plcp_header {
__le16 crc16;
} __attribute__((packed));
-static inline u8 zd_cck_plcp_header_rate(const struct cck_plcp_header *header)
+static inline u8 zd_cck_plcp_header_signal(const struct cck_plcp_header *header)
{
return header->signal;
}
-#define ZD_CCK_SIGNAL_1M 0x0a
-#define ZD_CCK_SIGNAL_2M 0x14
-#define ZD_CCK_SIGNAL_5M5 0x37
-#define ZD_CCK_SIGNAL_11M 0x6e
+/* These defines give the encodings of the signal field in the 802.11b PLCP
+ * header. The signal field gives the bit rate of the following packet. Even
+ * if technically wrong we use CCK here also for the 1 MBit/s and 2 MBit/s
+ * rate to stay consistent with Zydas and our use of the term.
+ *
+ * Notify that these values are *not* used in the zd-rates.
+ */
+#define ZD_CCK_PLCP_SIGNAL_1M 0x0a
+#define ZD_CCK_PLCP_SIGNAL_2M 0x14
+#define ZD_CCK_PLCP_SIGNAL_5M5 0x37
+#define ZD_CCK_PLCP_SIGNAL_11M 0x6e
enum ieee80211_std {
IEEE80211B = 0x01,
Index: linux/drivers/net/wireless/zd1211rw/zd_mac.c
===================================================================
--- linux.orig/drivers/net/wireless/zd1211rw/zd_mac.c
+++ linux/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -582,28 +582,6 @@ u8 zd_mac_get_channel(struct zd_mac *mac
return channel;
}
-/* If wrong rate is given, we are falling back to the slowest rate: 1MBit/s */
-static u8 zd_rate_typed(u8 zd_rate)
-{
- static const u8 typed_rates[16] = {
- [ZD_CCK_RATE_1M] = ZD_CS_CCK|ZD_CCK_RATE_1M,
- [ZD_CCK_RATE_2M] = ZD_CS_CCK|ZD_CCK_RATE_2M,
- [ZD_CCK_RATE_5_5M] = ZD_CS_CCK|ZD_CCK_RATE_5_5M,
- [ZD_CCK_RATE_11M] = ZD_CS_CCK|ZD_CCK_RATE_11M,
- [ZD_OFDM_RATE_6M] = ZD_CS_OFDM|ZD_OFDM_RATE_6M,
- [ZD_OFDM_RATE_9M] = ZD_CS_OFDM|ZD_OFDM_RATE_9M,
- [ZD_OFDM_RATE_12M] = ZD_CS_OFDM|ZD_OFDM_RATE_12M,
- [ZD_OFDM_RATE_18M] = ZD_CS_OFDM|ZD_OFDM_RATE_18M,
- [ZD_OFDM_RATE_24M] = ZD_CS_OFDM|ZD_OFDM_RATE_24M,
- [ZD_OFDM_RATE_36M] = ZD_CS_OFDM|ZD_OFDM_RATE_36M,
- [ZD_OFDM_RATE_48M] = ZD_CS_OFDM|ZD_OFDM_RATE_48M,
- [ZD_OFDM_RATE_54M] = ZD_CS_OFDM|ZD_OFDM_RATE_54M,
- };
-
- ZD_ASSERT(ZD_CS_RATE_MASK == 0x0f);
- return typed_rates[zd_rate & ZD_CS_RATE_MASK];
-}
-
int zd_mac_set_mode(struct zd_mac *mac, u32 mode)
{
struct ieee80211_device *ieee;
@@ -707,25 +685,30 @@ int zd_mac_get_range(struct zd_mac *mac,
static int zd_calc_tx_length_us(u8 *service, u8 zd_rate, u16 tx_length)
{
+ /* ZD_PURE_RATE() must be used to remove the modulation type flag of
+ * the zd-rate values. */
static const u8 rate_divisor[] = {
- [ZD_CCK_RATE_1M] = 1,
- [ZD_CCK_RATE_2M] = 2,
- [ZD_CCK_RATE_5_5M] = 11, /* bits must be doubled */
- [ZD_CCK_RATE_11M] = 11,
- [ZD_OFDM_RATE_6M] = 6,
- [ZD_OFDM_RATE_9M] = 9,
- [ZD_OFDM_RATE_12M] = 12,
- [ZD_OFDM_RATE_18M] = 18,
- [ZD_OFDM_RATE_24M] = 24,
- [ZD_OFDM_RATE_36M] = 36,
- [ZD_OFDM_RATE_48M] = 48,
- [ZD_OFDM_RATE_54M] = 54,
+ [ZD_PURE_RATE(ZD_CCK_RATE_1M)] = 1,
+ [ZD_PURE_RATE(ZD_CCK_RATE_2M)] = 2,
+
+ /* bits must be doubled */
+ [ZD_PURE_RATE(ZD_CCK_RATE_5_5M)] = 11,
+
+ [ZD_PURE_RATE(ZD_CCK_RATE_11M)] = 11,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_6M)] = 6,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_9M)] = 9,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_12M)] = 12,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_18M)] = 18,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_24M)] = 24,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_36M)] = 36,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_48M)] = 48,
+ [ZD_PURE_RATE(ZD_OFDM_RATE_54M)] = 54,
};
u32 bits = (u32)tx_length * 8;
u32 divisor;
- divisor = rate_divisor[zd_rate];
+ divisor = rate_divisor[ZD_PURE_RATE(zd_rate)];
if (divisor == 0)
return -EINVAL;
@@ -748,52 +731,24 @@ static int zd_calc_tx_length_us(u8 *serv
return bits/divisor;
}
-enum {
- R2M_SHORT_PREAMBLE = 0x01,
- R2M_11A = 0x02,
-};
-
-static u8 zd_rate_to_modulation(u8 zd_rate, int flags)
-{
- u8 modulation;
-
- modulation = zd_rate_typed(zd_rate);
- if (flags & R2M_SHORT_PREAMBLE) {
- switch (ZD_CS_RATE(modulation)) {
- case ZD_CCK_RATE_2M:
- case ZD_CCK_RATE_5_5M:
- case ZD_CCK_RATE_11M:
- modulation |= ZD_CS_CCK_PREA_SHORT;
- return modulation;
- }
- }
- if (flags & R2M_11A) {
- if (ZD_CS_TYPE(modulation) == ZD_CS_OFDM)
- modulation |= ZD_CS_OFDM_MODE_11A;
- }
- return modulation;
-}
-
static void cs_set_modulation(struct zd_mac *mac, struct zd_ctrlset *cs,
struct ieee80211_hdr_4addr *hdr)
{
struct ieee80211softmac_device *softmac = ieee80211_priv(mac->netdev);
u16 ftype = WLAN_FC_GET_TYPE(le16_to_cpu(hdr->frame_ctl));
- u8 rate, zd_rate;
+ u8 rate;
int is_mgt = (ftype == IEEE80211_FTYPE_MGMT) != 0;
int is_multicast = is_multicast_ether_addr(hdr->addr1);
int short_preamble = ieee80211softmac_short_preamble_ok(softmac,
is_multicast, is_mgt);
- int flags = 0;
- /* FIXME: 802.11a? */
rate = ieee80211softmac_suggest_txrate(softmac, is_multicast, is_mgt);
+ cs->modulation = rate_to_zd_rate(rate);
- if (short_preamble)
- flags |= R2M_SHORT_PREAMBLE;
-
- zd_rate = rate_to_zd_rate(rate);
- cs->modulation = zd_rate_to_modulation(zd_rate, flags);
+ /* Set short preamble bit when appropriate */
+ if (short_preamble && ZD_MODULATION_TYPE(cs->modulation) == ZD_CCK
+ && cs->modulation != ZD_CCK_RATE_1M)
+ cs->modulation |= ZD_CCK_PREA_SHORT;
}
static void cs_set_control(struct zd_mac *mac, struct zd_ctrlset *cs,
@@ -832,7 +787,7 @@ static void cs_set_control(struct zd_mac
cs->control |= ZD_CS_RTS;
/* Use CTS-to-self protection if required */
- if (ZD_CS_TYPE(cs->modulation) == ZD_CS_OFDM &&
+ if (ZD_MODULATION_TYPE(cs->modulation) == ZD_OFDM &&
ieee80211softmac_protection_needed(softmac)) {
/* FIXME: avoid sending RTS *and* self-CTS, is that correct? */
cs->control &= ~ZD_CS_RTS;
@@ -893,7 +848,7 @@ static int fill_ctrlset(struct zd_mac *m
* - see line 53 of zdinlinef.h
*/
cs->service = 0;
- r = zd_calc_tx_length_us(&cs->service, ZD_CS_RATE(cs->modulation),
+ r = zd_calc_tx_length_us(&cs->service, ZD_RATE(cs->modulation),
le16_to_cpu(cs->tx_length));
if (r < 0)
return r;
@@ -902,7 +857,7 @@ static int fill_ctrlset(struct zd_mac *m
if (next_frag_len == 0) {
cs->next_frame_length = 0;
} else {
- r = zd_calc_tx_length_us(NULL, ZD_CS_RATE(cs->modulation),
+ r = zd_calc_tx_length_us(NULL, ZD_RATE(cs->modulation),
next_frag_len);
if (r < 0)
return r;
Index: linux/drivers/net/wireless/zd1211rw/zd_mac.h
===================================================================
--- linux.orig/drivers/net/wireless/zd1211rw/zd_mac.h
+++ linux/drivers/net/wireless/zd1211rw/zd_mac.h
@@ -40,28 +40,51 @@ struct zd_ctrlset {
#define ZD_CS_RESERVED_SIZE 25
-/* zd_crtlset field modulation */
-#define ZD_CS_RATE_MASK 0x0f
-#define ZD_CS_TYPE_MASK 0x10
-#define ZD_CS_RATE(modulation) ((modulation) & ZD_CS_RATE_MASK)
-#define ZD_CS_TYPE(modulation) ((modulation) & ZD_CS_TYPE_MASK)
-
-#define ZD_CS_CCK 0x00
-#define ZD_CS_OFDM 0x10
-
-/* These are referred to as zd_rates */
-#define ZD_CCK_RATE_1M 0x00
-#define ZD_CCK_RATE_2M 0x01
-#define ZD_CCK_RATE_5_5M 0x02
-#define ZD_CCK_RATE_11M 0x03
-/* The rates for OFDM are encoded as in the PLCP header. Use ZD_OFDM_RATE_*.
+/* The field modulation of struct zd_ctrlset controls the bit rate, the use
+ * of short or long preambles in 802.11b (CCK mode) or the use of 802.11a or
+ * 802.11g in OFDM mode.
+ *
+ * The term zd-rate is used for the combination of the modulation type flag
+ * and the "pure" rate value.
*/
+#define ZD_PURE_RATE_MASK 0x0f
+#define ZD_MODULATION_TYPE_MASK 0x10
+#define ZD_RATE_MASK (ZD_PURE_RATE_MASK|ZD_MODULATION_TYPE_MASK)
+#define ZD_PURE_RATE(modulation) ((modulation) & ZD_PURE_RATE_MASK)
+#define ZD_MODULATION_TYPE(modulation) ((modulation) & ZD_MODULATION_TYPE_MASK)
+#define ZD_RATE(modulation) ((modulation) & ZD_RATE_MASK)
+
+/* The two possible modulation types. Notify that 802.11b doesn't use the CCK
+ * codeing for the 1 and 2 MBit/s rate. We stay with the term here to remain
+ * consistent with uses the term at other places.
+ */
+#define ZD_CCK 0x00
+#define ZD_OFDM 0x10
+
+/* The ZD1211 firmware uses proprietary encodings of the 802.11b (CCK) rates.
+ * For OFDM the PLCP rate encodings are used. We combine these "pure" rates
+ * with the modulation type flag and call the resulting values zd-rates.
+ */
+#define ZD_CCK_RATE_1M (ZD_CCK|0x00)
+#define ZD_CCK_RATE_2M (ZD_CCK|0x01)
+#define ZD_CCK_RATE_5_5M (ZD_CCK|0x02)
+#define ZD_CCK_RATE_11M (ZD_CCK|0x03)
+#define ZD_OFDM_RATE_6M (ZD_OFDM|ZD_OFDM_PLCP_RATE_6M)
+#define ZD_OFDM_RATE_9M (ZD_OFDM|ZD_OFDM_PLCP_RATE_9M)
+#define ZD_OFDM_RATE_12M (ZD_OFDM|ZD_OFDM_PLCP_RATE_12M)
+#define ZD_OFDM_RATE_18M (ZD_OFDM|ZD_OFDM_PLCP_RATE_18M)
+#define ZD_OFDM_RATE_24M (ZD_OFDM|ZD_OFDM_PLCP_RATE_24M)
+#define ZD_OFDM_RATE_36M (ZD_OFDM|ZD_OFDM_PLCP_RATE_36M)
+#define ZD_OFDM_RATE_48M (ZD_OFDM|ZD_OFDM_PLCP_RATE_48M)
+#define ZD_OFDM_RATE_54M (ZD_OFDM|ZD_OFDM_PLCP_RATE_54M)
-/* bit 5 is preamble (when in CCK mode), or a/g selection (when in OFDM mode) */
-#define ZD_CS_CCK_PREA_LONG 0x00
-#define ZD_CS_CCK_PREA_SHORT 0x20
-#define ZD_CS_OFDM_MODE_11G 0x00
-#define ZD_CS_OFDM_MODE_11A 0x20
+/* The bit 5 of the zd_ctrlset modulation field controls the preamble in CCK
+ * mode or the 802.11a/802.11g selection in OFDM mode.
+ */
+#define ZD_CCK_PREA_LONG 0x00
+#define ZD_CCK_PREA_SHORT 0x20
+#define ZD_OFDM_MODE_11G 0x00
+#define ZD_OFDM_MODE_11A 0x20
/* zd_ctrlset control field */
#define ZD_CS_NEED_RANDOM_BACKOFF 0x01
-
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