rt2800usb: add timer to handle TX_STA_FIFO

TX status is reported by the hardware when a packet has been
sent (or after TX failed after possible retries), which is some
time after the DMA completion.  Since the rt2800usb hardware can
not signal interrupts we have to use a timer, otherwise the
TX status would only be read by the next packet's TX DMA
completion, or by the watchdog thread.

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>

diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index 69004b968122f625d3b31fc38ded5f18f7c89ead..20059727ef80be8af6a37e35296f4876e6f3d164 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -98,6 +98,22 @@ static void rt2800usb_stop_queue(struct data_queue *queue)
        }
 }
 
+/*
+ * test if there is an entry in any TX queue for which DMA is done
+ * but the TX status has not been returned yet
+ */
+static bool rt2800usb_txstatus_pending(struct rt2x00_dev *rt2x00dev)
+{
+       struct data_queue *queue;
+
+       tx_queue_for_each(rt2x00dev, queue) {
+               if (rt2x00queue_get_entry(queue, Q_INDEX_DMA_DONE) !=
+                   rt2x00queue_get_entry(queue, Q_INDEX_DONE))
+                       return true;
+       }
+       return false;
+}
+
 static void rt2800usb_tx_sta_fifo_read_completed(struct rt2x00_dev *rt2x00dev,
                                                 int urb_status, u32 tx_status)
 {
@@ -115,8 +131,11 @@ static void rt2800usb_tx_sta_fifo_read_completed(struct rt2x00_dev *rt2x00dev,
                } else
                        rt2x00usb_register_read_async(rt2x00dev, TX_STA_FIFO,
                                                      rt2800usb_tx_sta_fifo_read_completed);
-       } else if (!kfifo_is_empty(&rt2x00dev->txstatus_fifo))
+       } else if (!kfifo_is_empty(&rt2x00dev->txstatus_fifo)) {
                queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+       } else if (rt2800usb_txstatus_pending(rt2x00dev)) {
+               mod_timer(&rt2x00dev->txstatus_timer, jiffies + msecs_to_jiffies(20));
+       }
 }
 
 static void rt2800usb_tx_dma_done(struct queue_entry *entry)
@@ -127,6 +146,14 @@ static void rt2800usb_tx_dma_done(struct queue_entry *entry)
                                      rt2800usb_tx_sta_fifo_read_completed);
 }
 
+static void rt2800usb_tx_sta_fifo_timeout(unsigned long data)
+{
+       struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
+
+       rt2x00usb_register_read_async(rt2x00dev, TX_STA_FIFO,
+                                     rt2800usb_tx_sta_fifo_read_completed);
+}
+
 /*
  * Firmware functions
  */
@@ -459,6 +486,14 @@ static void rt2800usb_work_txdone(struct work_struct *work)
                                break;
                }
        }
+
+       /*
+        * The hw may delay sending the packet after DMA complete
+        * if the medium is busy, thus the TX_STA_FIFO entry is
+        * also delayed -> use a timer to retrieve it.
+        */
+       if (rt2800usb_txstatus_pending(rt2x00dev))
+               mod_timer(&rt2x00dev->txstatus_timer, jiffies + msecs_to_jiffies(20));
 }
 
 /*
@@ -599,6 +634,10 @@ static int rt2800usb_probe_hw(struct rt2x00_dev *rt2x00dev)
        __set_bit(REQUIRE_HT_TX_DESC, &rt2x00dev->cap_flags);
        __set_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags);
 
+       setup_timer(&rt2x00dev->txstatus_timer,
+                   rt2800usb_tx_sta_fifo_timeout,
+                   (unsigned long) rt2x00dev);
+
        /*
         * Set the rssi offset.
         */

diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index e3b9b5146bf5ee2c5dc4f4db0c1e7d10cde9ee58..8f37121bb83f1ccf2bae8b47e7fc25eb02ec4866 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -37,6 +37,7 @@
 #include <linux/etherdevice.h>
 #include <linux/input-polldev.h>
 #include <linux/kfifo.h>
+#include <linux/timer.h>
 
 #include <net/mac80211.h>
 
@@ -923,6 +924,11 @@ struct rt2x00_dev {
         */
        DECLARE_KFIFO_PTR(txstatus_fifo, u32);
 
+       /*
+        * Timer to ensure tx status reports are read (rt2800usb).
+        */
+       struct timer_list txstatus_timer;
+
        /*
         * Tasklet for processing tx status reports (rt2800pci).
         */

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 2e490e0998da291a1b9d2edc15dac760c9bded6e..7776d9f1f29750ee3d4669e29c1bd708c8315888 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -1071,6 +1071,7 @@ void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
        /*
         * Stop all work.
         */
+       del_timer_sync(&rt2x00dev->txstatus_timer);
        cancel_work_sync(&rt2x00dev->intf_work);
        if (rt2x00_is_usb(rt2x00dev)) {
                cancel_work_sync(&rt2x00dev->rxdone_work);

diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 14736e217947fa39a1ba88da3da9ef02d600f658..34b8a887831bdd0d40ffa69dd82608394dc7ef55 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -280,7 +280,9 @@ static void rt2x00usb_interrupt_txdone(struct urb *urb)
         * Schedule the delayed work for reading the TX status
         * from the device.
         */
-       queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+       if (!test_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags) ||
+           !kfifo_is_empty(&rt2x00dev->txstatus_fifo))
+               queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
 }
 
 static bool rt2x00usb_kick_tx_entry(struct queue_entry *entry, void* data)
@@ -816,6 +818,7 @@ int rt2x00usb_probe(struct usb_interface *usb_intf,
 
        INIT_WORK(&rt2x00dev->rxdone_work, rt2x00usb_work_rxdone);
        INIT_WORK(&rt2x00dev->txdone_work, rt2x00usb_work_txdone);
+       init_timer(&rt2x00dev->txstatus_timer);
 
        retval = rt2x00usb_alloc_reg(rt2x00dev);
        if (retval)