From 0e0d39e5f3a3e59c8513b59d4feeeadcb93b707d Mon Sep 17 00:00:00 2001 From: Johannes Stezenbach Date: Mon, 18 Apr 2011 15:29:12 +0200 Subject: [PATCH] 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: Johannes Stezenbach Signed-off-by: Ivo van Doorn Signed-off-by: John W. Linville --- 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 */ -- 2.7.4