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| author | Josh Boyer <jwboyer@fedoraproject.org> | 2013-10-17 08:12:25 -0400 |
|---|---|---|
| committer | Josh Boyer <jwboyer@fedoraproject.org> | 2013-10-17 08:13:57 -0400 |
| commit | b980a8cb560cf1d81648a8b11467b412ac35f56e (patch) | |
| tree | 60efba1e9c3f6d71889d98a8d9444765d72e2db2 /rt2800usb-slow-down-TX-status-polling.patch | |
| parent | c517fd6ab4345254dc5d18793de6f7cfd51e4d43 (diff) | |
| download | kernel-b980a8cb560cf1d81648a8b11467b412ac35f56e.tar.gz kernel-b980a8cb560cf1d81648a8b11467b412ac35f56e.tar.xz kernel-b980a8cb560cf1d81648a8b11467b412ac35f56e.zip | |
Fix rt2800usb polling timeouts and throughput issues (rhbz 984696)
Diffstat (limited to 'rt2800usb-slow-down-TX-status-polling.patch')
| -rw-r--r-- | rt2800usb-slow-down-TX-status-polling.patch | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/rt2800usb-slow-down-TX-status-polling.patch b/rt2800usb-slow-down-TX-status-polling.patch new file mode 100644 index 000000000..a76f9b847 --- /dev/null +++ b/rt2800usb-slow-down-TX-status-polling.patch @@ -0,0 +1,53 @@ +Polling TX statuses too frequently has two negative effects. First is +randomly peek CPU usage, causing overall system functioning delays. +Second bad effect is that device is not able to fill TX statuses in +H/W register on some workloads and we get lot of timeouts like below: + +ieee80211 phy4: rt2800usb_entry_txstatus_timeout: Warning - TX status timeout for entry 7 in queue 2 +ieee80211 phy4: rt2800usb_entry_txstatus_timeout: Warning - TX status timeout for entry 7 in queue 2 +ieee80211 phy4: rt2800usb_txdone: Warning - Got TX status for an empty queue 2, dropping + +This not only cause flood of messages in dmesg, but also bad throughput, +since rate scaling algorithm can not work optimally. + +In the future, we should probably make polling interval be adjusted +automatically, but for now just increase values, this make mentioned +problems gone. + +Resolve: +https://bugzilla.kernel.org/show_bug.cgi?id=62781 + +Cc: stable@vger.kernel.org +Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> +--- + drivers/net/wireless/rt2x00/rt2800usb.c | 8 ++++---- + 1 file changed, 4 insertions(+), 4 deletions(-) + +diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c +index 96677ce5..e095e61 100644 +--- a/drivers/net/wireless/rt2x00/rt2800usb.c ++++ b/drivers/net/wireless/rt2x00/rt2800usb.c +@@ -176,8 +176,8 @@ static bool rt2800usb_tx_sta_fifo_read_completed(struct rt2x00_dev *rt2x00dev, + queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work); + + if (rt2800usb_txstatus_pending(rt2x00dev)) { +- /* Read register after 250 us */ +- hrtimer_start(&rt2x00dev->txstatus_timer, ktime_set(0, 250000), ++ /* Read register after 1 ms */ ++ hrtimer_start(&rt2x00dev->txstatus_timer, ktime_set(0, 1000000), + HRTIMER_MODE_REL); + return false; + } +@@ -202,8 +202,8 @@ 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), ++ /* Read TX_STA_FIFO register after 2 ms */ ++ hrtimer_start(&rt2x00dev->txstatus_timer, ktime_set(0, 2000000), + HRTIMER_MODE_REL); + } + +-- +1.8.3.1 |