rt2x00: rt2800usb: rework txstatus code
Currently we read tx status register after each urb data transfer. As
callback procedure also trigger reading, that causing we have many
"threads" of reading status. To prevent that introduce TX_STATUS_READING
flags, and check if we are already in process of sequential reading
TX_STA_FIFO, before requesting new reads.
Change timer to hrtimer, that make TX_STA_FIFO overruns less possible.
Use 200 us for initial timeout, and then reschedule in 100 us period,
this values probably have to be tuned.
Make changes on txdone work. Schedule it from
rt2800usb_tx_sta_fifo_read_completed() callback when first valid status
show up. Check in callback if tx status timeout happens, and schedule
work on that condition too. That make possible to remove tx status
timeout from generic watchdog. I moved that to rt2800usb.
Loop in txdone work, that should prevent situation when we queue work,
which is already processed, and after finish work is not rescheduled
again.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.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 4eaa628..eacf94b 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -114,45 +114,103 @@
return false;
}
+static inline bool rt2800usb_entry_txstatus_timeout(struct queue_entry *entry)
+{
+ bool tout;
+
+ if (!test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
+ return false;
+
+ tout = time_after(jiffies, entry->last_action + msecs_to_jiffies(100));
+ if (unlikely(tout))
+ WARNING(entry->queue->rt2x00dev,
+ "TX status timeout for entry %d in queue %d\n",
+ entry->entry_idx, entry->queue->qid);
+ return tout;
+
+}
+
+static bool rt2800usb_txstatus_timeout(struct rt2x00_dev *rt2x00dev)
+{
+ struct data_queue *queue;
+ struct queue_entry *entry;
+
+ tx_queue_for_each(rt2x00dev, queue) {
+ entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
+ if (rt2800usb_entry_txstatus_timeout(entry))
+ return true;
+ }
+ return false;
+}
+
static bool rt2800usb_tx_sta_fifo_read_completed(struct rt2x00_dev *rt2x00dev,
int urb_status, u32 tx_status)
{
+ bool valid;
+
if (urb_status) {
- WARNING(rt2x00dev, "rt2x00usb_register_read_async failed: %d\n", urb_status);
+ WARNING(rt2x00dev, "TX status read failed %d\n", urb_status);
+
+ goto stop_reading;
+ }
+
+ valid = rt2x00_get_field32(tx_status, TX_STA_FIFO_VALID);
+ if (valid) {
+ if (!kfifo_put(&rt2x00dev->txstatus_fifo, &tx_status))
+ WARNING(rt2x00dev, "TX status FIFO overrun\n");
+
+ queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+
+ /* Reschedule urb to read TX status again instantly */
+ return true;
+ } else if (rt2800usb_txstatus_pending(rt2x00dev)) {
+ /* Read register after 250 us */
+ hrtimer_start(&rt2x00dev->txstatus_timer, ktime_set(0, 250000),
+ HRTIMER_MODE_REL);
return false;
}
- /* 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
- return true;
- } 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(2));
- }
+stop_reading:
+ clear_bit(TX_STATUS_READING, &rt2x00dev->flags);
+ /*
+ * There is small race window above, between txstatus pending check and
+ * clear_bit someone could do rt2x00usb_interrupt_txdone, so recheck
+ * here again if status reading is needed.
+ */
+ if (rt2800usb_txstatus_pending(rt2x00dev) &&
+ test_and_set_bit(TX_STATUS_READING, &rt2x00dev->flags))
+ return true;
+ else
+ return false;
+}
- return false;
+static void rt2800usb_async_read_tx_status(struct rt2x00_dev *rt2x00dev)
+{
+
+ if (test_and_set_bit(TX_STATUS_READING, &rt2x00dev->flags))
+ return;
+
+ /* Read TX_STA_FIFO register after 500 us */
+ hrtimer_start(&rt2x00dev->txstatus_timer, ktime_set(0, 500000),
+ HRTIMER_MODE_REL);
}
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);
+ rt2800usb_async_read_tx_status(rt2x00dev);
}
-static void rt2800usb_tx_sta_fifo_timeout(unsigned long data)
+static enum hrtimer_restart rt2800usb_tx_sta_fifo_timeout(struct hrtimer *timer)
{
- struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
+ struct rt2x00_dev *rt2x00dev =
+ container_of(timer, struct rt2x00_dev, txstatus_timer);
rt2x00usb_register_read_async(rt2x00dev, TX_STA_FIFO,
rt2800usb_tx_sta_fifo_read_completed);
+
+ return HRTIMER_NORESTART;
}
/*
@@ -540,7 +598,7 @@
if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
rt2x00lib_txdone_noinfo(entry, TXDONE_FAILURE);
- else if (rt2x00queue_status_timeout(entry))
+ else if (rt2800usb_entry_txstatus_timeout(entry))
rt2x00lib_txdone_noinfo(entry, TXDONE_UNKNOWN);
else
break;
@@ -553,17 +611,21 @@
struct rt2x00_dev *rt2x00dev =
container_of(work, struct rt2x00_dev, txdone_work);
- rt2800usb_txdone(rt2x00dev);
+ while (!kfifo_is_empty(&rt2x00dev->txstatus_fifo) ||
+ rt2800usb_txstatus_timeout(rt2x00dev)) {
- rt2800usb_txdone_nostatus(rt2x00dev);
+ rt2800usb_txdone(rt2x00dev);
- /*
- * 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(2));
+ rt2800usb_txdone_nostatus(rt2x00dev);
+
+ /*
+ * 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))
+ rt2800usb_async_read_tx_status(rt2x00dev);
+ }
}
/*
@@ -705,9 +767,7 @@
__set_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags);
__set_bit(REQUIRE_PS_AUTOWAKE, &rt2x00dev->cap_flags);
- setup_timer(&rt2x00dev->txstatus_timer,
- rt2800usb_tx_sta_fifo_timeout,
- (unsigned long) rt2x00dev);
+ rt2x00dev->txstatus_timer.function = rt2800usb_tx_sta_fifo_timeout,
/*
* Set the rssi offset.
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 65275ef..471f87ca 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -38,7 +38,7 @@
#include <linux/etherdevice.h>
#include <linux/input-polldev.h>
#include <linux/kfifo.h>
-#include <linux/timer.h>
+#include <linux/hrtimer.h>
#include <net/mac80211.h>
@@ -692,6 +692,12 @@
*/
CONFIG_CHANNEL_HT40,
CONFIG_POWERSAVING,
+
+ /*
+ * Mark we currently are sequentially reading TX_STA_FIFO register
+ * FIXME: this is for only rt2800usb, should go to private data
+ */
+ TX_STATUS_READING,
};
/*
@@ -974,7 +980,7 @@
/*
* Timer to ensure tx status reports are read (rt2800usb).
*/
- struct timer_list txstatus_timer;
+ struct hrtimer 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 49a51b4..cffcf2e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -1232,7 +1232,7 @@
cancel_delayed_work_sync(&rt2x00dev->autowakeup_work);
cancel_work_sync(&rt2x00dev->sleep_work);
if (rt2x00_is_usb(rt2x00dev)) {
- del_timer_sync(&rt2x00dev->txstatus_timer);
+ hrtimer_cancel(&rt2x00dev->txstatus_timer);
cancel_work_sync(&rt2x00dev->rxdone_work);
cancel_work_sync(&rt2x00dev->txdone_work);
}
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index 349008d..5f1392c 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -636,18 +636,6 @@
{
return rt2x00queue_available(queue) < queue->threshold;
}
-
-/**
- * rt2x00queue_status_timeout - Check if a timeout occurred for STATUS reports
- * @entry: Queue entry to check.
- */
-static inline int rt2x00queue_status_timeout(struct queue_entry *entry)
-{
- if (!test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
- return false;
- return time_after(jiffies, entry->last_action + msecs_to_jiffies(100));
-}
-
/**
* rt2x00queue_dma_timeout - Check if a timeout occurred for DMA transfers
* @entry: Queue entry to check.
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 2eea386..66094eb 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -526,22 +526,6 @@
rt2x00queue_flush_queue(queue, true);
}
-static void rt2x00usb_watchdog_tx_status(struct data_queue *queue)
-{
- WARNING(queue->rt2x00dev, "TX queue %d status timed out,"
- " invoke forced tx handler\n", queue->qid);
-
- queue_work(queue->rt2x00dev->workqueue, &queue->rt2x00dev->txdone_work);
-}
-
-static int rt2x00usb_status_timeout(struct data_queue *queue)
-{
- struct queue_entry *entry;
-
- entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
- return rt2x00queue_status_timeout(entry);
-}
-
static int rt2x00usb_dma_timeout(struct data_queue *queue)
{
struct queue_entry *entry;
@@ -558,8 +542,6 @@
if (!rt2x00queue_empty(queue)) {
if (rt2x00usb_dma_timeout(queue))
rt2x00usb_watchdog_tx_dma(queue);
- if (rt2x00usb_status_timeout(queue))
- rt2x00usb_watchdog_tx_status(queue);
}
}
}
@@ -829,7 +811,8 @@
INIT_WORK(&rt2x00dev->rxdone_work, rt2x00usb_work_rxdone);
INIT_WORK(&rt2x00dev->txdone_work, rt2x00usb_work_txdone);
- init_timer(&rt2x00dev->txstatus_timer);
+ hrtimer_init(&rt2x00dev->txstatus_timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
retval = rt2x00usb_alloc_reg(rt2x00dev);
if (retval)