From: Johannes Stezenbach <js@xxxxxxxxx>
Trying to fix the "TX status report missed" warnings
by reading the TX_STA_FIFO entries as quickly as possible.
The TX_STA_FIFO is too small in hardware, thus reading
it only from the workqueue is too slow and entries get lost.
Start an asynchronous read of the TX_STA_FIFO directly from
the TX URB completion callback (atomic context, thus it cannot
use the blocking rt2800_register_read()). If the async
read returns a valid FIFO entry, it is pushed into a larger
FIFO inside struct rt2x00_dev, until rt2800_txdone() picks
it up.
A .tx_dma_done callback is added to struct rt2x00lib_ops
to trigger the async read from the URB completion callback.
Signed-off-by: Johannes Stezenbach <js@xxxxxxxxx>
Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
---
drivers/net/wireless/rt2x00/rt2800lib.c | 34 ++++++--------------
drivers/net/wireless/rt2x00/rt2800usb.c | 31 ++++++++++++++++++
drivers/net/wireless/rt2x00/rt2x00.h | 1 +
drivers/net/wireless/rt2x00/rt2x00usb.c | 53 +++++++++++++++++++++++++++++++
drivers/net/wireless/rt2x00/rt2x00usb.h | 15 +++++++++
5 files changed, 110 insertions(+), 24 deletions(-)
diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index 0e2c006..d79c8fd 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -730,34 +730,20 @@ void rt2800_txdone(struct rt2x00_dev *rt2x00dev)
struct data_queue *queue;
struct queue_entry *entry;
u32 reg;
- u8 pid;
- int i;
+ u8 qid;
- /*
- * TX_STA_FIFO is a stack of X entries, hence read TX_STA_FIFO
- * at most X times and also stop processing once the TX_STA_FIFO_VALID
- * flag is not set anymore.
- *
- * The legacy drivers use X=TX_RING_SIZE but state in a comment
- * that the TX_STA_FIFO stack has a size of 16. We stick to our
- * tx ring size for now.
- */
- for (i = 0; i < rt2x00dev->ops->tx->entry_num; i++) {
- rt2800_register_read(rt2x00dev, TX_STA_FIFO, ®);
- if (!rt2x00_get_field32(reg, TX_STA_FIFO_VALID))
- break;
+ while (kfifo_get(&rt2x00dev->txstatus_fifo, ®)) {
- /*
- * Skip this entry when it contains an invalid
- * queue identication number.
+ /* TX_STA_FIFO_PID_QUEUE is a 2-bit field, thus
+ * qid is guaranteed to be one of the TX QIDs
*/
- pid = rt2x00_get_field32(reg, TX_STA_FIFO_PID_QUEUE);
- if (pid >= QID_RX)
- continue;
-
- queue = rt2x00queue_get_tx_queue(rt2x00dev, pid);
- if (unlikely(!queue))
+ qid = rt2x00_get_field32(reg, TX_STA_FIFO_PID_QUEUE);
+ queue = rt2x00queue_get_tx_queue(rt2x00dev, qid);
+ if (unlikely(!queue)) {
+ WARNING(rt2x00dev, "Got TX status for an unavailable "
+ "queue %u, dropping\n", qid);
continue;
+ }
/*
* Inside each queue, we process each entry in a chronological
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index f3ce5e8..862430e 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -98,6 +98,35 @@ static void rt2800usb_stop_queue(struct data_queue *queue)
}
}
+static void rt2800usb_tx_sta_fifo_read_completed(struct rt2x00_dev *rt2x00dev,
+ int urb_status, u32 tx_status)
+{
+ if (urb_status) {
+ WARNING(rt2x00dev, "rt2x00usb_register_read_async failed: %d\n", urb_status);
+ return;
+ }
+
+ /* try to read all TX_STA_FIFO entries before scheduling txdone_work */
+ if (rt2x00_get_field32(tx_status, TX_STA_FIFO_VALID)) {
+ if (!kfifo_put(&rt2x00dev->txstatus_fifo, &tx_status)) {
+ WARNING(rt2x00dev, "TX status FIFO overrun, "
+ "drop tx status report.\n");
+ queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+ } else
+ rt2x00usb_register_read_async(rt2x00dev, TX_STA_FIFO,
+ rt2800usb_tx_sta_fifo_read_completed);
+ } else if (!kfifo_is_empty(&rt2x00dev->txstatus_fifo))
+ queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+}
+
+static void rt2800usb_tx_dma_done(struct queue_entry *entry)
+{
+ struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
+
+ rt2x00usb_register_read_async(rt2x00dev, TX_STA_FIFO,
+ rt2800usb_tx_sta_fifo_read_completed);
+}
+
/*
* Firmware functions
*/
@@ -565,6 +594,7 @@ static int rt2800usb_probe_hw(struct rt2x00_dev *rt2x00dev)
__set_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags);
__set_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags);
__set_bit(REQUIRE_HT_TX_DESC, &rt2x00dev->cap_flags);
+ __set_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags);
/*
* Set the rssi offset.
@@ -635,6 +665,7 @@ static const struct rt2x00lib_ops rt2800usb_rt2x00_ops = {
.kick_queue = rt2x00usb_kick_queue,
.stop_queue = rt2800usb_stop_queue,
.flush_queue = rt2x00usb_flush_queue,
+ .tx_dma_done = rt2800usb_tx_dma_done,
.write_tx_desc = rt2800usb_write_tx_desc,
.write_tx_data = rt2800usb_write_tx_data,
.write_beacon = rt2800_write_beacon,
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 79c385a..e3b9b51 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -571,6 +571,7 @@ struct rt2x00lib_ops {
void (*kick_queue) (struct data_queue *queue);
void (*stop_queue) (struct data_queue *queue);
void (*flush_queue) (struct data_queue *queue);
+ void (*tx_dma_done) (struct queue_entry *entry);
/*
* TX control handlers
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 0bc8dcc..5fbab6f 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -165,6 +165,56 @@ int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
}
EXPORT_SYMBOL_GPL(rt2x00usb_regbusy_read);
+
+struct rt2x00_async_read_data {
+ __le32 reg;
+ struct usb_ctrlrequest cr;
+ struct rt2x00_dev *rt2x00dev;
+ void (*callback)(struct rt2x00_dev *,int,u32);
+};
+
+static void rt2x00usb_register_read_async_cb(struct urb *urb)
+{
+ struct rt2x00_async_read_data *rd = urb->context;
+ rd->callback(rd->rt2x00dev, urb->status, le32_to_cpu(rd->reg));
+ kfree(urb->context);
+}
+
+void rt2x00usb_register_read_async(struct rt2x00_dev *rt2x00dev,
+ const unsigned int offset,
+ void (*callback)(struct rt2x00_dev*,int,u32))
+{
+ struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
+ struct urb *urb;
+ struct rt2x00_async_read_data *rd;
+
+ rd = kmalloc(sizeof(*rd), GFP_ATOMIC);
+ if (!rd)
+ return;
+
+ urb = usb_alloc_urb(0, GFP_ATOMIC);
+ if (!urb) {
+ kfree(rd);
+ return;
+ }
+
+ rd->rt2x00dev = rt2x00dev;
+ rd->callback = callback;
+ rd->cr.bRequestType = USB_VENDOR_REQUEST_IN;
+ rd->cr.bRequest = USB_MULTI_READ;
+ rd->cr.wValue = 0;
+ rd->cr.wIndex = cpu_to_le16(offset);
+ rd->cr.wLength = cpu_to_le16(sizeof(u32));
+
+ usb_fill_control_urb(urb, usb_dev, usb_rcvctrlpipe(usb_dev, 0),
+ (unsigned char *)(&rd->cr), &rd->reg, sizeof(rd->reg),
+ rt2x00usb_register_read_async_cb, rd);
+ if (usb_submit_urb(urb, GFP_ATOMIC) < 0)
+ kfree(rd);
+ usb_free_urb(urb);
+}
+EXPORT_SYMBOL_GPL(rt2x00usb_register_read_async);
+
/*
* TX data handlers.
*/
@@ -212,6 +262,9 @@ static void rt2x00usb_interrupt_txdone(struct urb *urb)
if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
return;
+ if (rt2x00dev->ops->lib->tx_dma_done)
+ rt2x00dev->ops->lib->tx_dma_done(entry);
+
/*
* Report the frame as DMA done
*/
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.h b/drivers/net/wireless/rt2x00/rt2x00usb.h
index 6aaf51f..e3faca6 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.h
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.h
@@ -345,6 +345,21 @@ int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
const struct rt2x00_field32 field,
u32 *reg);
+/**
+ * rt2x00usb_register_read_async - Asynchronously read 32bit register word
+ * @rt2x00dev: Device pointer, see &struct rt2x00_dev.
+ * @offset: Register offset
+ * @callback: Functon to call when read completes.
+ *
+ * Submit a control URB to read a 32bit register. This safe to
+ * be called from atomic context. The callback will be called
+ * when the URB completes. Otherwise the function is similar
+ * to rt2x00usb_register_read().
+ */
+void rt2x00usb_register_read_async(struct rt2x00_dev *rt2x00dev,
+ const unsigned int offset,
+ void (*callback)(struct rt2x00_dev*,int,u32));
+
/*
* Radio handlers
*/
--
1.7.2.3
--
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