Re: [PATCH 2/2] Input: atmel_mxt_ts - fix double free of input device

From: Nick Dyer
Date: Wed Sep 10 2014 - 10:32:01 EST


On 10/09/14 00:49, Dmitry Torokhov wrote:
> On Tue, Sep 09, 2014 at 03:50:49PM +0100, nick.dyer@xxxxxxxxxxx wrote:
>> From: Stephen Warren <swarren@xxxxxxxxxxxxx>
>>
>> [reworked after comments by Dmitry Torokhov. Move free of input device into
>> separate function. Only call in paths that require it. Move mxt_initialize
>> after sysfs init, because otherwise an error in the sysfs init may interfere
>> with the async return from the firmware loader. Add guards for sysfs
>> functions. ]
>
> Ugh... there is still problem with asycn firmware loading: you need to
> make sure it is done before you try to unbind the dveice. I also do not
> see what stops several firmware update requests to happen
> simultaneously. Once you add proper handling for that you can use the
> same lock in sysfs read methods.

Yes, I see what you mean. I will try and straighten it out.

> Another option is wait a bit and see what's the outcome of async probing
> discussion on LKML is and maybe we can stop using
> request_firmware_nowait() in probe path but rather have device core fire
> off probe asynchronously.
>
> I'd rather have fix for input device freeing be separate from
> sysfs/firmware/config loading changes.

I agree, it is better to fix the common issue with a straightforward patch.
I have split it apart and will send this patch now.
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