2022-07-21 22:41:36

by Sean Wang

Subject: [PATCH v2 1/2] mt76: sdio: fix the deadlock caused by sdio->stat_work

From: Sean Wang <[email protected]>

Because wake_work and sdio->stat_work share the same workqueue mt76->wq,
if sdio->stat_work cannot acquire the mutex lock such as that was possibly
held up by [mt7615, mt7921]_mutex_acquire. Additionally, if
[mt7615, mt7921]_mutex_acquire was called by sdio->stat_work self, the wake
would be blocked by itself. Thus, we move the stat_work into
ieee80211_workqueue instead to break the deadlock.

Fixes: d39b52e31aa6 ("mt76: introduce mt76_sdio module")
Co-developed-by: YN Chen <[email protected]>
Signed-off-by: YN Chen <[email protected]>
Signed-off-by: Sean Wang <[email protected]>
---
v2: move state_work to ieee80211_workqueue and update git message
---
drivers/net/wireless/mediatek/mt76/sdio.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/sdio.c b/drivers/net/wireless/mediatek/mt76/sdio.c
index aba2a9865821..fb2caeae6dba 100644
--- a/drivers/net/wireless/mediatek/mt76/sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/sdio.c
@@ -481,7 +481,7 @@ static void mt76s_status_worker(struct mt76_worker *w)
if (dev->drv->tx_status_data &&
!test_and_set_bit(MT76_READING_STATS, &dev->phy.state) &&
!test_bit(MT76_STATE_SUSPEND, &dev->phy.state))
- queue_work(dev->wq, &dev->sdio.stat_work);
+ ieee80211_queue_work(dev->hw, &dev->sdio.stat_work);
} while (nframes > 0);

if (resched)
@@ -508,7 +508,7 @@ static void mt76s_tx_status_data(struct work_struct *work)
}

if (count && test_bit(MT76_STATE_RUNNING, &dev->phy.state))
- queue_work(dev->wq, &sdio->stat_work);
+ ieee80211_queue_work(dev->hw, &sdio->stat_work);
else
clear_bit(MT76_READING_STATS, &dev->phy.state);
}
--
2.25.1

2022-07-21 22:44:00

by Sean Wang

Subject: [PATCH v2 2/2] mt76: sdio: poll sta stat when device transmits data

From: Sean Wang <[email protected]>

It is not meaningful to poll sta stat when there is no data traffic.
So polling sta stat when the device has transmitted data instead to save
CPU power.

That implies that it is unallowed the stat_work to work while MCU is being
initialized in the really early stage to fix the possible time to time MCU
initialization failure.

Fixes: d39b52e31aa6 ("mt76: introduce mt76_sdio module")
Signed-off-by: Sean Wang <[email protected]>
---
v2: update the commit message
---
drivers/net/wireless/mediatek/mt76/sdio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/sdio.c b/drivers/net/wireless/mediatek/mt76/sdio.c
index fb2caeae6dba..ece4e4bb94a1 100644
--- a/drivers/net/wireless/mediatek/mt76/sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/sdio.c
@@ -478,7 +478,7 @@ static void mt76s_status_worker(struct mt76_worker *w)
if (ndata_frames > 0)
resched = true;

- if (dev->drv->tx_status_data &&
+ if (dev->drv->tx_status_data && ndata_frames > 0 &&
!test_and_set_bit(MT76_READING_STATS, &dev->phy.state) &&
!test_bit(MT76_STATE_SUSPEND, &dev->phy.state))
ieee80211_queue_work(dev->hw, &dev->sdio.stat_work);
--
2.25.1