From: Kalle Valo <kvalo@qca.qualcomm.com>
To: Michal Kazior <michal.kazior@tieto.com>
Cc: linux-wireless <linux-wireless@vger.kernel.org>,
"ath10k@lists.infradead.org" <ath10k@lists.infradead.org>
Subject: Re: [PATCH v2 3/5] ath10k: drain tx before restarting hw
Date: Fri, 23 May 2014 13:31:01 +0300 [thread overview]
Message-ID: <877g5cvlay.fsf@kamboji.qca.qualcomm.com> (raw)
In-Reply-To: <CA+BoTQn_V5zGA18qGMNrWYy_-fBQzBi1=EmzMs=0SLvk1LBVJQ@mail.gmail.com> (Michal Kazior's message of "Fri, 23 May 2014 11:06:25 +0200")
Michal Kazior <michal.kazior@tieto.com> writes:
>> Sure, but I still think it's a bit ugly. The right way to fix this would
>> be to add it to include/lockdep.h, instead of adding custom checks to a
>> driver.
>
> Good point. I wonder if it's generic enough to justify.
No idea. But no matter what it will take some time to get it accepted,
so we need to solve this in a faster way so that I can apply this patch.
>> But does this check even make sense? There's nothing preventing
>> to another thread to take lock just after the WARN_ON(), right?
>
> There's nothing wrong with other thread holding it. Actually that's
> the reason for this very check.
>
> The point is to prevent ath10k_drain_tx() being called while caller
> (current thread) holds conf_mutex. If it were to hold conf_mutex then
> cancel_work_sync() can deadlock as both workers it tries to stop try
> to get a hold of the lock too.
Ah, now I understand.
What if we just drop the WARN_ON() from this patch just so that I can
apply the patch and we add a proper code for checking the mutex in a
followup patch? Are you ok with that?
--
Kalle Valo
_______________________________________________
ath10k mailing list
ath10k@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/ath10k
WARNING: multiple messages have this Message-ID (diff)
From: Kalle Valo <kvalo@qca.qualcomm.com>
To: Michal Kazior <michal.kazior@tieto.com>
Cc: "ath10k@lists.infradead.org" <ath10k@lists.infradead.org>,
linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH v2 3/5] ath10k: drain tx before restarting hw
Date: Fri, 23 May 2014 13:31:01 +0300 [thread overview]
Message-ID: <877g5cvlay.fsf@kamboji.qca.qualcomm.com> (raw)
In-Reply-To: <CA+BoTQn_V5zGA18qGMNrWYy_-fBQzBi1=EmzMs=0SLvk1LBVJQ@mail.gmail.com> (Michal Kazior's message of "Fri, 23 May 2014 11:06:25 +0200")
Michal Kazior <michal.kazior@tieto.com> writes:
>> Sure, but I still think it's a bit ugly. The right way to fix this would
>> be to add it to include/lockdep.h, instead of adding custom checks to a
>> driver.
>
> Good point. I wonder if it's generic enough to justify.
No idea. But no matter what it will take some time to get it accepted,
so we need to solve this in a faster way so that I can apply this patch.
>> But does this check even make sense? There's nothing preventing
>> to another thread to take lock just after the WARN_ON(), right?
>
> There's nothing wrong with other thread holding it. Actually that's
> the reason for this very check.
>
> The point is to prevent ath10k_drain_tx() being called while caller
> (current thread) holds conf_mutex. If it were to hold conf_mutex then
> cancel_work_sync() can deadlock as both workers it tries to stop try
> to get a hold of the lock too.
Ah, now I understand.
What if we just drop the WARN_ON() from this patch just so that I can
apply the patch and we add a proper code for checking the mutex in a
followup patch? Are you ok with that?
--
Kalle Valo
next prev parent reply other threads:[~2014-05-23 10:31 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-09 12:15 [PATCH 0/5] ath10k: recovery fixes 2014-05-09 Michal Kazior
2014-05-09 12:15 ` Michal Kazior
2014-05-09 12:15 ` [PATCH 1/5] ath10k: clean up start() callback Michal Kazior
2014-05-09 12:15 ` Michal Kazior
2014-05-14 19:07 ` Kalle Valo
2014-05-14 19:07 ` Kalle Valo
2014-05-09 12:15 ` [PATCH 2/5] ath10k: perform hw restart lazily Michal Kazior
2014-05-09 12:15 ` Michal Kazior
2014-05-09 12:15 ` [PATCH 3/5] ath10k: drain tx before restarting hw Michal Kazior
2014-05-09 12:15 ` Michal Kazior
2014-05-09 12:15 ` [PATCH 4/5] ath10k: protect wep tx key setup Michal Kazior
2014-05-09 12:15 ` Michal Kazior
2014-05-14 19:17 ` Kalle Valo
2014-05-14 19:17 ` Kalle Valo
2014-05-14 19:50 ` Kalle Valo
2014-05-14 19:50 ` Kalle Valo
2014-05-15 6:04 ` Michal Kazior
2014-05-15 6:04 ` Michal Kazior
2014-05-09 12:15 ` [PATCH 5/5] ath10k: dont configure bssid for ap mode Michal Kazior
2014-05-09 12:15 ` Michal Kazior
2014-05-14 18:58 ` Kalle Valo
2014-05-14 18:58 ` Kalle Valo
2014-05-15 8:41 ` [PATCH v2 0/5] ath10k: recovery fixes 2014-05-09 Michal Kazior
2014-05-15 8:41 ` Michal Kazior
2014-05-15 8:42 ` [PATCH v2 1/5] ath10k: clean up start() callback Michal Kazior
2014-05-15 8:42 ` Michal Kazior
2014-05-15 8:42 ` [PATCH v2 2/5] ath10k: perform hw restart lazily Michal Kazior
2014-05-15 8:42 ` Michal Kazior
2014-05-15 8:42 ` [PATCH v2 3/5] ath10k: drain tx before restarting hw Michal Kazior
2014-05-15 8:42 ` Michal Kazior
2014-05-15 13:18 ` Kalle Valo
2014-05-15 13:18 ` Kalle Valo
2014-05-16 14:37 ` Kalle Valo
2014-05-16 14:37 ` Kalle Valo
2014-05-23 8:27 ` Kalle Valo
2014-05-23 8:27 ` Kalle Valo
2014-05-23 8:38 ` Michal Kazior
2014-05-23 8:38 ` Michal Kazior
2014-05-23 8:45 ` Kalle Valo
2014-05-23 8:45 ` Kalle Valo
2014-05-23 9:06 ` Michal Kazior
2014-05-23 9:06 ` Michal Kazior
2014-05-23 10:31 ` Kalle Valo [this message]
2014-05-23 10:31 ` Kalle Valo
2014-05-23 10:37 ` Michal Kazior
2014-05-23 10:37 ` Michal Kazior
2014-05-23 13:03 ` Johannes Berg
2014-05-23 13:03 ` Johannes Berg
2014-05-26 5:48 ` Michal Kazior
2014-05-26 5:48 ` Michal Kazior
2014-05-26 6:29 ` Johannes Berg
2014-05-26 6:29 ` Johannes Berg
2014-05-26 9:40 ` Kalle Valo
2014-05-26 9:40 ` Kalle Valo
2014-05-26 9:43 ` Michal Kazior
2014-05-26 9:43 ` Michal Kazior
2014-05-15 8:42 ` [PATCH v2 4/5] ath10k: protect wep tx key setup Michal Kazior
2014-05-15 8:42 ` Michal Kazior
2014-05-15 8:42 ` [PATCH v2 5/5] ath10k: dont configure bssid for ap mode Michal Kazior
2014-05-15 8:42 ` Michal Kazior
2014-05-27 9:29 ` [PATCH v2 0/5] ath10k: recovery fixes 2014-05-09 Kalle Valo
2014-05-27 9:29 ` 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=877g5cvlay.fsf@kamboji.qca.qualcomm.com \
--to=kvalo@qca.qualcomm.com \
--cc=ath10k@lists.infradead.org \
--cc=linux-wireless@vger.kernel.org \
--cc=michal.kazior@tieto.com \
/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.