[PATCH 23/33] drm/vc4: hdmi: Move HDMI reset to pm_resume

[Florian Fainelli]

On 8/4/22 16:11, Florian Fainelli wrote:
> On 6/13/22 07:47, Maxime Ripard wrote:
>> From: Dave Stevenson <dave.stevenson at raspberrypi.com>
>>
>> The BCM2835-37 found in the RaspberryPi 0 to 3 have a power domain
>> attached to the HDMI block, handled in Linux through runtime_pm.
>>
>> That power domain is shared with the VEC block, so even if we put our
>> runtime_pm reference in the HDMI driver it would keep being on. If the
>> VEC is disabled though, the power domain would be disabled and we would
>> lose any initialization done in our bind implementation.
>>
>> That initialization involves calling the reset function and initializing
>> the CEC registers.
>>
>> Let's move the initialization to our runtime_resume implementation so
>> that we initialize everything properly if we ever need to.
>>
>> Fixes: c86b41214362 ("drm/vc4: hdmi: Move the HSM clock enable to 
>> runtime_pm")
>> Signed-off-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
>> Signed-off-by: Maxime Ripard <maxime at cerno.tech>
> 
> After seeing the same warning as Stefan reported in the link below, but 
> on the Raspberry Pi 4B:
> 
> https://www.spinics.net/lists/dri-devel/msg354170.html
> 
> a separate bisection effort led me to this commit, before is fine, after 
> produces 4 warnings during boot, see attached log.
> 
> Is there a fix that we can try that would also cover the Raspberry Pi 
> 4B? Is it possible that this series precipitates the problem:
> 
> https://www.spinics.net/lists/arm-kernel/msg984638.html

Maxime, Dave, anything you would want me to try? Still seeing these 
warnings with net-next-6.0-11220-g15205c2829ca

Would be nice to see those fixes before 6.0 final, thanks!
-- 
Florian