Commit 0e0d39e5 authored by Johannes Stezenbach's avatar Johannes Stezenbach Committed by John W. Linville

rt2800usb: read TX_STA_FIFO asynchronously

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: default avatarJohannes Stezenbach <js@sig21.net>
Signed-off-by: default avatarIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 8da3efbb
...@@ -730,34 +730,20 @@ void rt2800_txdone(struct rt2x00_dev *rt2x00dev) ...@@ -730,34 +730,20 @@ void rt2800_txdone(struct rt2x00_dev *rt2x00dev)
struct data_queue *queue; struct data_queue *queue;
struct queue_entry *entry; struct queue_entry *entry;
u32 reg; u32 reg;
u8 pid; u8 qid;
int i;
/* while (kfifo_get(&rt2x00dev->txstatus_fifo, &reg)) {
* 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, &reg);
if (!rt2x00_get_field32(reg, TX_STA_FIFO_VALID))
break;
/* /* TX_STA_FIFO_PID_QUEUE is a 2-bit field, thus
* Skip this entry when it contains an invalid * qid is guaranteed to be one of the TX QIDs
* queue identication number.
*/ */
pid = rt2x00_get_field32(reg, TX_STA_FIFO_PID_QUEUE); qid = rt2x00_get_field32(reg, TX_STA_FIFO_PID_QUEUE);
if (pid >= QID_RX) queue = rt2x00queue_get_tx_queue(rt2x00dev, qid);
continue; if (unlikely(!queue)) {
WARNING(rt2x00dev, "Got TX status for an unavailable "
queue = rt2x00queue_get_tx_queue(rt2x00dev, pid); "queue %u, dropping\n", qid);
if (unlikely(!queue))
continue; continue;
}
/* /*
* Inside each queue, we process each entry in a chronological * Inside each queue, we process each entry in a chronological
......
...@@ -98,6 +98,35 @@ static void rt2800usb_stop_queue(struct data_queue *queue) ...@@ -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 * Firmware functions
*/ */
...@@ -565,6 +594,7 @@ static int rt2800usb_probe_hw(struct rt2x00_dev *rt2x00dev) ...@@ -565,6 +594,7 @@ static int rt2800usb_probe_hw(struct rt2x00_dev *rt2x00dev)
__set_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags); __set_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags);
__set_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags); __set_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags);
__set_bit(REQUIRE_HT_TX_DESC, &rt2x00dev->cap_flags); __set_bit(REQUIRE_HT_TX_DESC, &rt2x00dev->cap_flags);
__set_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags);
/* /*
* Set the rssi offset. * Set the rssi offset.
...@@ -635,6 +665,7 @@ static const struct rt2x00lib_ops rt2800usb_rt2x00_ops = { ...@@ -635,6 +665,7 @@ static const struct rt2x00lib_ops rt2800usb_rt2x00_ops = {
.kick_queue = rt2x00usb_kick_queue, .kick_queue = rt2x00usb_kick_queue,
.stop_queue = rt2800usb_stop_queue, .stop_queue = rt2800usb_stop_queue,
.flush_queue = rt2x00usb_flush_queue, .flush_queue = rt2x00usb_flush_queue,
.tx_dma_done = rt2800usb_tx_dma_done,
.write_tx_desc = rt2800usb_write_tx_desc, .write_tx_desc = rt2800usb_write_tx_desc,
.write_tx_data = rt2800usb_write_tx_data, .write_tx_data = rt2800usb_write_tx_data,
.write_beacon = rt2800_write_beacon, .write_beacon = rt2800_write_beacon,
......
...@@ -571,6 +571,7 @@ struct rt2x00lib_ops { ...@@ -571,6 +571,7 @@ struct rt2x00lib_ops {
void (*kick_queue) (struct data_queue *queue); void (*kick_queue) (struct data_queue *queue);
void (*stop_queue) (struct data_queue *queue); void (*stop_queue) (struct data_queue *queue);
void (*flush_queue) (struct data_queue *queue); void (*flush_queue) (struct data_queue *queue);
void (*tx_dma_done) (struct queue_entry *entry);
/* /*
* TX control handlers * TX control handlers
......
...@@ -165,6 +165,56 @@ int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev, ...@@ -165,6 +165,56 @@ int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
} }
EXPORT_SYMBOL_GPL(rt2x00usb_regbusy_read); 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. * TX data handlers.
*/ */
...@@ -212,6 +262,9 @@ static void rt2x00usb_interrupt_txdone(struct urb *urb) ...@@ -212,6 +262,9 @@ static void rt2x00usb_interrupt_txdone(struct urb *urb)
if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
return; return;
if (rt2x00dev->ops->lib->tx_dma_done)
rt2x00dev->ops->lib->tx_dma_done(entry);
/* /*
* Report the frame as DMA done * Report the frame as DMA done
*/ */
......
...@@ -345,6 +345,21 @@ int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev, ...@@ -345,6 +345,21 @@ int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
const struct rt2x00_field32 field, const struct rt2x00_field32 field,
u32 *reg); 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 * Radio handlers
*/ */
......
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