3 files changed, 188 insertions, 13 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c
index 005ee153e0cc..3806454b827b 100644
--- a/drivers/net/wireless/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/rt2x00/rt2800pci.c
@@ -660,6 +660,63 @@ static void rt2800pci_wakeup(struct rt2x00_dev *rt2x00dev)
         rt2800_config(rt2x00dev, &libconf, IEEE80211_CONF_CHANGE_PS);
 }
 
+static void rt2800pci_txdone(struct rt2x00_dev *rt2x00dev)
+{
+        struct data_queue *queue;
+        struct queue_entry *entry;
+        u32 status;
+        u8 qid;
+
+        while (!kfifo_is_empty(&rt2x00dev->txstatus_fifo)) {
+                /* Now remove the tx status from the FIFO */
+                if (kfifo_out(&rt2x00dev->txstatus_fifo, &status,
+                              sizeof(status)) != sizeof(status)) {
+                        WARN_ON(1);
+                        break;
+                }
+
+                qid = rt2x00_get_field32(status, TX_STA_FIFO_PID_TYPE) - 1;
+                if (qid >= QID_RX) {
+                        /*
+                         * Unknown queue, this shouldn't happen. Just drop
+                         * this tx status.
+                         */
+                        WARNING(rt2x00dev, "Got TX status report with "
+                                           "unexpected pid %u, dropping", qid);
+                        break;
+                }
+
+                queue = rt2x00queue_get_queue(rt2x00dev, qid);
+                if (unlikely(queue == NULL)) {
+                        /*
+                         * The queue is NULL, this shouldn't happen. Stop
+                         * processing here and drop the tx status
+                         */
+                        WARNING(rt2x00dev, "Got TX status for an unavailable "
+                                           "queue %u, dropping", qid);
+                        break;
+                }
+
+                if (rt2x00queue_empty(queue)) {
+                        /*
+                         * The queue is empty. Stop processing here
+                         * and drop the tx status.
+                         */
+                        WARNING(rt2x00dev, "Got TX status for an empty "
+                                           "queue %u, dropping", qid);
+                        break;
+                }
+
+                entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
+                rt2800_txdone_entry(entry, status);
+        }
+}
+
+static void rt2800pci_txstatus_tasklet(unsigned long data)
+{
+        rt2800pci_txdone((struct rt2x00_dev *)data);
+}
+
 static irqreturn_t rt2800pci_interrupt_thread(int irq, void *dev_instance)
 {
         struct rt2x00_dev *rt2x00dev = dev_instance;
@@ -684,13 +741,7 @@ static irqreturn_t rt2800pci_interrupt_thread(int irq, void *dev_instance)
                 rt2x00pci_rxdone(rt2x00dev);
 
         /*
-         * 4 - Tx done interrupt.
-         */
-        if (rt2x00_get_field32(reg, INT_SOURCE_CSR_TX_FIFO_STATUS))
-                rt2800_txdone(rt2x00dev);
-
-        /*
-         * 5 - Auto wakeup interrupt.
+         * 4 - Auto wakeup interrupt.
          */
         if (rt2x00_get_field32(reg, INT_SOURCE_CSR_AUTO_WAKEUP))
                 rt2800pci_wakeup(rt2x00dev);
@@ -702,10 +753,58 @@ static irqreturn_t rt2800pci_interrupt_thread(int irq, void *dev_instance)
         return IRQ_HANDLED;
 }
 
+static void rt2800pci_txstatus_interrupt(struct rt2x00_dev *rt2x00dev)
+{
+        u32 status;
+        int i;
+
+        /*
+         * The TX_FIFO_STATUS interrupt needs special care. We should
+         * read TX_STA_FIFO but we should do it immediately as otherwise
+         * the register can overflow and we would lose status reports.
+         *
+         * Hence, read the TX_STA_FIFO register and copy all tx status
+         * reports into a kernel FIFO which is handled in the txstatus
+         * tasklet. We use a tasklet to process the tx status reports
+         * because we can schedule the tasklet multiple times (when the
+         * interrupt fires again during tx status processing).
+         *
+         * Furthermore we don't disable the TX_FIFO_STATUS
+         * interrupt here but leave it enabled so that the TX_STA_FIFO
+         * can also be read while the interrupt thread gets executed.
+         *
+         * Since we have only one producer and one consumer we don't
+         * need to lock the kfifo.
+         */
+        for (i = 0; i < TX_ENTRIES; i++) {
+                rt2800_register_read(rt2x00dev, TX_STA_FIFO, &status);
+
+                if (!rt2x00_get_field32(status, TX_STA_FIFO_VALID))
+                        break;
+
+                if (kfifo_is_full(&rt2x00dev->txstatus_fifo)) {
+                        WARNING(rt2x00dev, "TX status FIFO overrun,"
+                                " drop tx status report.\n");
+                        break;
+                }
+
+                if (kfifo_in(&rt2x00dev->txstatus_fifo, &status,
+                             sizeof(status)) != sizeof(status)) {
+                        WARNING(rt2x00dev, "TX status FIFO overrun,"
+                                "drop tx status report.\n");
+                        break;
+                }
+        }
+
+        /* Schedule the tasklet for processing the tx status. */
+        tasklet_schedule(&rt2x00dev->txstatus_tasklet);
+}
+
 static irqreturn_t rt2800pci_interrupt(int irq, void *dev_instance)
 {
         struct rt2x00_dev *rt2x00dev = dev_instance;
         u32 reg;
+        irqreturn_t ret = IRQ_HANDLED;
 
         /* Read status and ACK all interrupts */
         rt2800_register_read(rt2x00dev, INT_SOURCE_CSR, &reg);
@@ -717,15 +816,38 @@ static irqreturn_t rt2800pci_interrupt(int irq, void *dev_instance)
         if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                 return IRQ_HANDLED;
 
-        /* Store irqvalue for use in the interrupt thread. */
-        rt2x00dev->irqvalue[0] = reg;
+        if (rt2x00_get_field32(reg, INT_SOURCE_CSR_TX_FIFO_STATUS))
+                rt2800pci_txstatus_interrupt(rt2x00dev);
+
+        if (rt2x00_get_field32(reg, INT_SOURCE_CSR_PRE_TBTT) ||
+            rt2x00_get_field32(reg, INT_SOURCE_CSR_TBTT) ||
+            rt2x00_get_field32(reg, INT_SOURCE_CSR_RX_DONE) ||
+            rt2x00_get_field32(reg, INT_SOURCE_CSR_AUTO_WAKEUP)) {
+                /*
+                 * All other interrupts are handled in the interrupt thread.
+                 * Store irqvalue for use in the interrupt thread.
+                 */
+                rt2x00dev->irqvalue[0] = reg;
 
-        /* Disable interrupts, will be enabled again in the interrupt thread. */
-        rt2x00dev->ops->lib->set_device_state(rt2x00dev,
-                                              STATE_RADIO_IRQ_OFF_ISR);
+                /*
+                 * Disable interrupts, will be enabled again in the
+                 * interrupt thread.
+                */
+                rt2x00dev->ops->lib->set_device_state(rt2x00dev,
+                                                      STATE_RADIO_IRQ_OFF_ISR);
 
+                /*
+                 * Leave the TX_FIFO_STATUS interrupt enabled to not lose any
+                 * tx status reports.
+                 */
+                rt2800_register_read(rt2x00dev, INT_MASK_CSR, &reg);
+                rt2x00_set_field32(&reg, INT_MASK_CSR_TX_FIFO_STATUS, 1);
+                rt2800_register_write(rt2x00dev, INT_MASK_CSR, reg);
 
-        return IRQ_WAKE_THREAD;
+                ret = IRQ_WAKE_THREAD;
+        }
+
+        return ret;
 }
 
 /*
@@ -788,6 +910,7 @@ static int rt2800pci_probe_hw(struct rt2x00_dev *rt2x00dev)
                 __set_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags);
         __set_bit(DRIVER_REQUIRE_DMA, &rt2x00dev->flags);
         __set_bit(DRIVER_REQUIRE_L2PAD, &rt2x00dev->flags);
+        __set_bit(DRIVER_REQUIRE_TXSTATUS_FIFO, &rt2x00dev->flags);
         if (!modparam_nohwcrypt)
                 __set_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags);
         __set_bit(DRIVER_SUPPORT_LINK_TUNING, &rt2x00dev->flags);
@@ -837,6 +960,7 @@ static const struct rt2800_ops rt2800pci_rt2800_ops = {
 static const struct rt2x00lib_ops rt2800pci_rt2x00_ops = {
         .irq_handler            = rt2800pci_interrupt,
         .irq_handler_thread     = rt2800pci_interrupt_thread,
+        .txstatus_tasklet       = rt2800pci_txstatus_tasklet,
         .probe_hw               = rt2800pci_probe_hw,
         .get_firmware_name      = rt2800pci_get_firmware_name,
         .check_firmware         = rt2800_check_firmware,
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 7832a5996a8c..bab10adae537 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -36,6 +36,7 @@
 #include <linux/mutex.h>
 #include <linux/etherdevice.h>
 #include <linux/input-polldev.h>
+#include <linux/kfifo.h>
 
 #include <net/mac80211.h>
 
@@ -522,6 +523,11 @@ struct rt2x00lib_ops {
         irq_handler_t irq_handler_thread;
 
         /*
+         * TX status tasklet handler.
+         */
+        void (*txstatus_tasklet) (unsigned long data);
+
+        /*
          * Device init handlers.
          */
         int (*probe_hw) (struct rt2x00_dev *rt2x00dev);
@@ -651,6 +657,7 @@ enum rt2x00_flags {
         DRIVER_REQUIRE_DMA,
         DRIVER_REQUIRE_COPY_IV,
         DRIVER_REQUIRE_L2PAD,
+        DRIVER_REQUIRE_TXSTATUS_FIFO,
 
         /*
          * Driver features
@@ -884,6 +891,16 @@ struct rt2x00_dev {
          * and interrupt thread routine.
          */
         u32 irqvalue[2];
+
+        /*
+         * FIFO for storing tx status reports between isr and tasklet.
+         */
+        struct kfifo txstatus_fifo;
+
+        /*
+         * Tasklet for processing tx status reports (rt2800pci).
+         */
+        struct tasklet_struct txstatus_tasklet;
 };
 
 /*
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 053fdd3bd720..b03e6e41dc1e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -813,6 +813,30 @@ static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
                 rt2x00dev->hw->extra_tx_headroom += RT2X00_ALIGN_SIZE;
 
         /*
+         * Allocate tx status FIFO for driver use.
+         */
+        if (test_bit(DRIVER_REQUIRE_TXSTATUS_FIFO, &rt2x00dev->flags) &&
+            rt2x00dev->ops->lib->txstatus_tasklet) {
+                /*
+                 * Allocate txstatus fifo and tasklet, we use a size of 512
+                 * for the kfifo which is big enough to store 512/4=128 tx
+                 * status reports. In the worst case (tx status for all tx
+                 * queues gets reported before we've got a chance to handle
+                 * them) 24*4=384 tx status reports need to be cached.
+                 */
+                status = kfifo_alloc(&rt2x00dev->txstatus_fifo, 512,
+                                     GFP_KERNEL);
+                if (status)
+                        return status;
+
+                /* tasklet for processing the tx status reports. */
+                tasklet_init(&rt2x00dev->txstatus_tasklet,
+                             rt2x00dev->ops->lib->txstatus_tasklet,
+                             (unsigned long)rt2x00dev);
+
+        }
+
+        /*
          * Register HW.
          */
         status = ieee80211_register_hw(rt2x00dev->hw);
@@ -1028,6 +1052,16 @@ void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
         cancel_work_sync(&rt2x00dev->txdone_work);
 
         /*
+         * Free the tx status fifo.
+         */
+        kfifo_free(&rt2x00dev->txstatus_fifo);
+
+        /*
+         * Kill the tx status tasklet.
+         */
+        tasklet_kill(&rt2x00dev->txstatus_tasklet);
+
+        /*
          * Uninitialize device.
          */
         rt2x00lib_uninitialize(rt2x00dev);