Re: [PATCH] HID: uHID: fix excepted report type

[David Herrmann]

Hi

On Wed, Oct 1, 2014 at 5:59 PM, Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
> When uhid_get_report() or uhid_set_report() are called, they emit on the
> char device a UHID_GET_REPORT or UHID_SET_REPORT message. Then, the
> protocol says that the user space asnwers with UHID_GET_REPORT_REPLY
> or UHID_SET_REPORT_REPLY.
>
> Unfortunatelly, the current code waits for an event of type UHID_GET_REPORT
> or UHID_SET_REPORT instead of the reply one.
> Add 1 to UHID_GET_REPORT or UHID_SET_REPORT to actually wait for the
> reply, and validate the reply.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> ---
>
> Hi David,
>
> while playing with a Bluetooth LE mouse, I noticed that uhid did not validate
> properly the get_report feature. With this patch and some work on bluez, this
> part now works almost (at least I manage to get reports from the device, there
> is still a 0x0b header I can not rely to anything, so there will be some work
> to do in Bordeaux :) )
>
> Cheers,
> Benjamin
>
>  drivers/hid/uhid.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
> index f6ec5ea..e094c57 100644
> --- a/drivers/hid/uhid.c
> +++ b/drivers/hid/uhid.c
> @@ -154,7 +154,7 @@ static int __uhid_report_queue_and_wait(struct uhid_device *uhid,
>
>         spin_lock_irqsave(&uhid->qlock, flags);
>         *report_id = ++uhid->report_id;
> -       uhid->report_type = ev->type;
> +       uhid->report_type = ev->type + 1;

Nice catch. We always need the *_REPLY type as response:

Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx>

Thanks for trying to fix this! I will try to get my Arc-Surface
working until Bordeaux. We should be able to get all that stuff
figured out together then. And it will still be in time for 3.18-fixes
then.

Thanks
David

>         uhid->report_running = true;
>         uhid_queue(uhid, ev);
>         spin_unlock_irqrestore(&uhid->qlock, flags);
> --
> 1.9.3
>
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