Re: [PATCH] soc: imx: gpcv2: fix regulator deferred probe

From: Andrey Smirnov
Date: Thu Aug 03 2017 - 03:08:44 EST


On Wed, Aug 2, 2017 at 12:51 PM, Stefan Agner <stefan@xxxxxxxx> wrote:
> If a regulator requests a deferred probe, the power domain gets
> initialized twice. This leads to a list double add (without
> list debugging the kernel hangs due to the double add later):
>
> WARNING: CPU: 0 PID: 19 at lib/list_debug.c:31 __list_add_valid+0xbc/0xc4
> list_add double add: new=c1229754, prev=c12383b4, next=c1229754.
>
> Initialize the power domain after we get the regulator. Also do
> not print an error in case the regulator defers probing.
>
> Cc: Fabio Estevam <fabio.estevam@xxxxxxx>
> Cc: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Fixes: 03aa12629fc4 ("soc: imx: Add GPCv2 power gating driver")
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>

As the author of original bug:

Acked-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>

I also went ahead and tested PCIe on my SabreSD with Intel Gigabit adapter, so

Tested-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>

Thanks for debugging and fixing this!

Andrey Smirnov