Re: [PATCH AUTOSEL 4.18 023/131] media: usbtv: use irqsave() in USB's complete callback

[Sebastian Andrzej Siewior]

On 2018-09-02 13:03:27 [+0000], Sasha Levin wrote:
> From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> 
> [ 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@xxxxxxxxx>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>

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