Re: [PATCH] Input: wm97xx: only unregister wm97xx_driver if it has been registered

From: Charles Keepax
Date: Wed Sep 05 2018 - 05:16:19 EST


On Tue, Sep 04, 2018 at 07:35:05PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> In the case where IS_BUILTIN(CONFIG_AC97_BUS)) is not true, the
> wm97xx_driver driver is being unregistered even it has not been
> previously registered. Fix this by only unregistering it if
> IS_BUILTIN(CONFIG_AC97_BUS)) is true. This fixes the warning
> message:
>
> [ 834.111248] ------------[ cut here ]------------
> [ 834.111248] Unexpected driver unregister!
> [ 834.111319] WARNING: CPU: 2 PID: 11749 at drivers/base/driver.c:193 driver_unregister+0x3b/0x40
> [ 834.111319] Modules linked in: wm97xx_ts(-) ....
>
> ..and a stack trace.
>
> To easily reproduce this, load and unload the module on a system where
> the hardware is not supported.
>
> Fixes: ae9d1b5fbd7b ("Input: wm97xx: add new AC97 bus support")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---

Acked-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>

Thanks,
Charles