Re: [PATCH v2 0/1] platform/x86: asus-wmi: disable USB0 hub on ROG Ally before suspend

[Luke Jones <luke@ljones.dev>]

On Mon, Nov 27 2023 at 12:05:20 PM +13:00:00, Luke D. Jones 
<luke@ljones.dev> wrote:
> This is a fix for the ROG Ally not being able to use the N-Key device 
> after a suspend/resume cycle.
> 
> The root of the issue is that ASUS changed the MCU firmware to 
> dfisconnect the USB0 hub when the
> screen is switched off during the s2idle suspend path. I tried many 
> many different tactics to try
> and get this s2idle part to work but it seems there are races between 
> this and other subsystems.
> 
> What has so far been reliable and consistent is a manual call to the 
> CSEE method that is called in
> ACPI by the Microsoft DSM screen off path followed by a short sleep 
> in asus-wmi. The PM prepare
> hook looks to be the earliest possible place. A sleep that is too 
> long ends up with USB subsystem
> registering a disconnect, and thus on resume the device paths change. 
> Too short and it is unreliable.
> 
> Some discussion regarding this mess is at 
> https://gitlab.freedesktop.org/drm/amd/-/issues/2719#note_2181402
> 
> Changelog:
> - v2:
>   - Emit dev_err(), but don't return error codes
>   - Add check for MCU power save mode being enabled and disable if 
> active
>   - General cleanup and rename some vars/funcs
> - v1: 
> https://lore.kernel.org/all/20231124082749.23353-1-luke@ljones.dev/
> 
> Luke D. Jones (1):
>   platform/x86: asus-wmi: disable USB0 hub on ROG Ally before suspend
> 
>  drivers/platform/x86/asus-wmi.c            | 50 
> ++++++++++++++++++++++
>  include/linux/platform_data/x86/asus-wmi.h |  3 ++
>  2 files changed, 53 insertions(+)
> 
> --
> 2.43.0
> 

Hans I omitted your review tag as I made more changes than requested.