From: Soeren Moch <smoch@web.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, tglx@linutronix.de
Subject: Re: [PATCH] Revert "usb: core: remove local_irq_save() around ->complete() handler"
Date: Mon, 17 Jun 2019 12:12:19 +0200 [thread overview]
Message-ID: <23aebb29-db6f-95fb-5cad-10d9b45fcd57@web.de> (raw)
In-Reply-To: <20190612144747.mf7hwunsl2zi3uxo@linutronix.de>
On 12.06.19 16:47, Sebastian Andrzej Siewior wrote:
> On 2019-06-12 10:38:11 [-0400], Alan Stern wrote:
>>> When stopping hostapd after it hangs:
>>> [ 903.504475] ieee80211 phy0: rt2x00queue_flush_queue: Warning - Queue
>>> 14 failed to flush
>> Instead of reverting the original commit, can you prevent the problem
>> by adding local_irq_save() and local_irq_restore() to the URB
>> completion routines in that wireless driver?
>>
>> Probably people who aren't already pretty familiar with the driver code
>> won't easily be able to locate the race. Still, a little overkill may
>> be an acceptable solution.
> Not from RT point of view because you do
> local_irq_save() -> spin_lock()
>
> but it might be worth checking if the local_irq_save() within that
> wireless driver avoids the race or not.
I just sent a patch for the underlying problem in the rt2x00 driver, see
[1].
So we can drop this patch here and keep RT folks happy.
I really hope that no other usb drivers are affected by similar problems.
Zyxel support just sent me (some?) source code for the firmware of my
internet router (my real problem I mentioned before). Need to look into
this...
Thanks for your help,
Soeren
[1] https://lkml.org/lkml/2019/6/17/238
>> Alan Stern
> Sebastian
next prev parent reply other threads:[~2019-06-17 10:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-31 21:53 [PATCH] Revert "usb: core: remove local_irq_save() around ->complete() handler" Soeren Moch
2019-05-31 22:05 ` Greg Kroah-Hartman
2019-05-31 23:02 ` Soeren Moch
2019-06-01 10:50 ` Sebastian Andrzej Siewior
2019-06-01 11:02 ` Sebastian Andrzej Siewior
2019-06-03 12:50 ` Sören Moch
2019-06-12 10:38 ` Soeren Moch
2019-06-12 14:38 ` Alan Stern
2019-06-12 14:47 ` Sebastian Andrzej Siewior
2019-06-17 10:12 ` Soeren Moch [this message]
2019-06-03 12:47 ` Sören Moch
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