Re: [PATCH] HID: core: cleanup .claimed field on disconnect

[Jiri Kosina]

On Mon, 3 Nov 2014, Benjamin Tissoires wrote:

> When a subdriver is rmmod-ed then re-insmod-ed, the hid device is not
> destroyed as it is owned by the transport layer.
> So when we re-probed the device, the hid device is assumed to be already
> claimed, and can lead to page faults if hid-core tries to forward the
> emitted data to the to-be-created claimed node.
> 
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> ---
> 
> Hi Jiri,
> 
> [keeping the people involved in the logitech-hidpp driver in CC]
> 
> this one was particularly nasty. I had several page faults when just
> rmmod && insmod the hid-logitech-hidpp driver. The page fault was occuring
> in hidraw :/
> I was not able to get a stacktrace which I could include here. The laptop was
> completely unresponsive and I could take only a picture to debug it.

Thanks a lot for tracking it down, Benjamin, tricky one indeed. Queuing 
for 3.18 still.

-- 
Jiri Kosina
SUSE Labs
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