[2/2] mt76: mt7921: reduce the mutex lock scope during reset

Commit Message

Sean Wang June 23, 2022, 12:35 a.m. UTC

From: Sean Wang <[e-mail]>

Reduce the mutex lock scope for reset to get rid of possible task hung
e.g wpa_supplicant and to allow the user-space process to keep running
during we need more retries to complete the reset.

Suggested-by: YN Chen <[e-mail]>
Signed-off-by: Sean Wang <[e-mail]>
---
 drivers/net/wireless/mediatek/mt76/mt7921/mac.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

Comments

AngeloGioacchino Del Regno June 23, 2022, 8:56 a.m. UTC | #1

Il 23/06/22 02:35, [e-mail] ha scritto:
> From: Sean Wang <[e-mail]>
> 
> Reduce the mutex lock scope for reset to get rid of possible task hung
> e.g wpa_supplicant and to allow the user-space process to keep running
> during we need more retries to complete the reset.
> 

To actually, effectively, reduce the chance to get a hung task, and also
to improve the general responsiveness, I think that the best way would be
to manage the locking inside of the reset callback(s) for each dev/bus.

This is especially because some of these reset functions (like the SDIO one)
may end up waiting for more than *two seconds*.

However, I get that this proposal requires way more effort, and this commit
will anyway improve the situation as it is... so, you get my:

Reviewed-by: AngeloGioacchino Del Regno <[e-mail]>

> Suggested-by: YN Chen <[e-mail]>
> Signed-off-by: Sean Wang <[e-mail]>

Patch

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
index 2ce3a833176e..c7bca83e7686 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
@@ -738,7 +738,7 @@  void mt7921_mac_reset_work(struct work_struct *work)
 					      reset_work);
 	struct ieee80211_hw *hw = mt76_hw(dev);
 	struct mt76_connac_pm *pm = &dev->pm;
-	int i;
+	int i, ret;
 
 	dev_info(dev->mt76.dev, "chip reset\n");
 	dev->hw_full_reset = true;
@@ -748,11 +748,14 @@  void mt7921_mac_reset_work(struct work_struct *work)
 	cancel_delayed_work_sync(&pm->ps_work);
 	cancel_work_sync(&pm->wake_work);
 
-	mutex_lock(&dev->mt76.mutex);
-	for (i = 0; i < 10; i++)
-		if (!mt7921_dev_reset(dev))
+	for (i = 0; i < 10; i++) {
+		mutex_lock(&dev->mt76.mutex);
+		ret = mt7921_dev_reset(dev);
+		mutex_unlock(&dev->mt76.mutex);
+
+		if (!ret)
 			break;
-	mutex_unlock(&dev->mt76.mutex);
+	}
 
 	if (i == 10)
 		dev_err(dev->mt76.dev, "chip reset failed\n");