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rt2800usb: read TX_STA_FIFO asynchronously

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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@sig21.net>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Stezenbach
2011-04-18 15:29:12 +02:00
committed by John W. Linville
parent 8da3efbb4a
commit 0e0d39e5f3
5 changed files with 110 additions and 24 deletions
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53
drivers/net/wireless/rt2x00/rt2x00usb.c
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@ -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
*/