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Date:   Mon, 3 Sep 2018 09:16:32 +0200
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Sasha Levin <Alexander.Levin@microsoft.com>
Cc:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Hans Verkuil <hans.verkuil@cisco.com>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Subject: Re: [PATCH AUTOSEL 4.18 023/131] media: usbtv: use irqsave() in
 USB's complete callback
Message-ID: <20180903071631.phvvuwxu5ozstq6g@linutronix.de>
References: <20180902064601.183036-1-alexander.levin@microsoft.com>
 <20180902064601.183036-23-alexander.levin@microsoft.com>
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On 2018-09-02 13:03:27 [+0000], Sasha Levin wrote:
> From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> 
> [ Upstream commit 320905baa1dbddd3991c287432176d536e1d5b79 ]
> 
> The USB completion callback does not disable interrupts while acquiring
> the lock. We want to remove the local_irq_disable() invocation from
> __usb_hcd_giveback_urb() and therefore it is required for the callback
> handler to disable the interrupts while acquiring the lock.
> The callback may be invoked either in IRQ or BH context depending on the
> USB host controller.
> Use the _irqsave() variant of the locking primitives.
> 
> Cc: Hans Verkuil <hans.verkuil@cisco.com>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>

This change (among the others that do the same in different drivers)
does not fix a bug; it is just needed for "other reasons". While this
series uncovered a few bugs, this is not one of them.
There is no need to backport this stable.

Sebastian