All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
To: <ath10k@lists.infradead.org>
Cc: <mohammed@codeaurora.org>, <linux-wireless@vger.kernel.org>,
	"Mohammed Shafi Shajakhan" <mohammed@qti.qualcomm.com>
Subject: [PATCH v2] ath10k: Fix soft lockup during firmware crash/hw-restart
Date: Wed, 30 Nov 2016 10:59:29 +0530	[thread overview]
Message-ID: <1480483769-17693-1-git-send-email-mohammed@qca.qualcomm.com> (raw)

From: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>

During firmware crash (or) user requested manual restart
the system gets into a soft lock up state because of the
below root cause.

During user requested hardware restart / firmware crash
the system goes into a soft lockup state as 'napi_synchronize'
is called after 'napi_disable' (which sets 'NAPI_STATE_SCHED'
bit) and it sleeps into infinite loop as it waits for
'NAPI_STATE_SCHED' to be cleared. This condition is hit because
'ath10k_hif_stop' is called twice as below (resulting in calling
'napi_synchronize' after 'napi_disable')

'ath10k_core_restart' -> 'ath10k_hif_stop' (ATH10K_STATE_ON) ->
-> 'ieee80211_restart_hw' -> 'ath10k_start' -> 'ath10k_halt' ->
'ath10k_core_stop' -> 'ath10k_hif_stop' (ATH10K_STATE_RESTARTING)

Fix this by calling 'ath10k_halt' in ath10k_core_restart itself
as it makes more sense before informing mac80211 to restart h/w
Also remove 'ath10k_halt' in ath10k_start for the state of 'restarting'

Fixes: 3c97f5de1f28 ("ath10k: implement NAPI support")
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
---
[v2 Added Fixes ]

 drivers/net/wireless/ath/ath10k/core.c | 2 +-
 drivers/net/wireless/ath/ath10k/mac.c  | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 7005e2a..5bc6847 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -1536,7 +1536,7 @@ static void ath10k_core_restart(struct work_struct *work)
 	switch (ar->state) {
 	case ATH10K_STATE_ON:
 		ar->state = ATH10K_STATE_RESTARTING;
-		ath10k_hif_stop(ar);
+		ath10k_halt(ar);
 		ath10k_scan_finish(ar);
 		ieee80211_restart_hw(ar->hw);
 		break;
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 717b2fa..481842b 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -4449,7 +4449,6 @@ static int ath10k_start(struct ieee80211_hw *hw)
 		ar->state = ATH10K_STATE_ON;
 		break;
 	case ATH10K_STATE_RESTARTING:
-		ath10k_halt(ar);
 		ar->state = ATH10K_STATE_RESTARTED;
 		break;
 	case ATH10K_STATE_ON:
-- 
1.9.1

WARNING: multiple messages have this Message-ID (diff)
From: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
To: ath10k@lists.infradead.org
Cc: mohammed@codeaurora.org, linux-wireless@vger.kernel.org,
	Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
Subject: [PATCH v2] ath10k: Fix soft lockup during firmware crash/hw-restart
Date: Wed, 30 Nov 2016 10:59:29 +0530	[thread overview]
Message-ID: <1480483769-17693-1-git-send-email-mohammed@qca.qualcomm.com> (raw)

From: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>

During firmware crash (or) user requested manual restart
the system gets into a soft lock up state because of the
below root cause.

During user requested hardware restart / firmware crash
the system goes into a soft lockup state as 'napi_synchronize'
is called after 'napi_disable' (which sets 'NAPI_STATE_SCHED'
bit) and it sleeps into infinite loop as it waits for
'NAPI_STATE_SCHED' to be cleared. This condition is hit because
'ath10k_hif_stop' is called twice as below (resulting in calling
'napi_synchronize' after 'napi_disable')

'ath10k_core_restart' -> 'ath10k_hif_stop' (ATH10K_STATE_ON) ->
-> 'ieee80211_restart_hw' -> 'ath10k_start' -> 'ath10k_halt' ->
'ath10k_core_stop' -> 'ath10k_hif_stop' (ATH10K_STATE_RESTARTING)

Fix this by calling 'ath10k_halt' in ath10k_core_restart itself
as it makes more sense before informing mac80211 to restart h/w
Also remove 'ath10k_halt' in ath10k_start for the state of 'restarting'

Fixes: 3c97f5de1f28 ("ath10k: implement NAPI support")
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
---
[v2 Added Fixes ]

 drivers/net/wireless/ath/ath10k/core.c | 2 +-
 drivers/net/wireless/ath/ath10k/mac.c  | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 7005e2a..5bc6847 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -1536,7 +1536,7 @@ static void ath10k_core_restart(struct work_struct *work)
 	switch (ar->state) {
 	case ATH10K_STATE_ON:
 		ar->state = ATH10K_STATE_RESTARTING;
-		ath10k_hif_stop(ar);
+		ath10k_halt(ar);
 		ath10k_scan_finish(ar);
 		ieee80211_restart_hw(ar->hw);
 		break;
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 717b2fa..481842b 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -4449,7 +4449,6 @@ static int ath10k_start(struct ieee80211_hw *hw)
 		ar->state = ATH10K_STATE_ON;
 		break;
 	case ATH10K_STATE_RESTARTING:
-		ath10k_halt(ar);
 		ar->state = ATH10K_STATE_RESTARTED;
 		break;
 	case ATH10K_STATE_ON:
-- 
1.9.1


_______________________________________________
ath10k mailing list
ath10k@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/ath10k

             reply	other threads:[~2016-11-30  5:29 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-30  5:29 Mohammed Shafi Shajakhan [this message]
2016-11-30  5:29 ` [PATCH v2] ath10k: Fix soft lockup during firmware crash/hw-restart Mohammed Shafi Shajakhan
2016-12-01 10:35 ` Valo, Kalle
2016-12-01 10:35   ` Valo, Kalle
2016-12-01 11:12   ` Mohammed Shafi Shajakhan
2016-12-01 11:12     ` Mohammed Shafi Shajakhan
2016-12-01 11:13 ` [v2] " Kalle Valo
2016-12-01 11:13   ` Kalle Valo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1480483769-17693-1-git-send-email-mohammed@qca.qualcomm.com \
    --to=mohammed@qti.qualcomm.com \
    --cc=ath10k@lists.infradead.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=mohammed@codeaurora.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.