From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Soeren Moch <smoch@web.de>,
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: Wed, 12 Jun 2019 16:47:47 +0200 [thread overview]
Message-ID: <20190612144747.mf7hwunsl2zi3uxo@linutronix.de> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1906121033550.1557-100000@iolanthe.rowland.org>
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.
> Alan Stern
Sebastian
next prev parent reply other threads:[~2019-06-12 14:47 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 [this message]
2019-06-17 10:12 ` Soeren Moch
2019-06-03 12:47 ` Sören Moch
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