[PATCH 2/4] drm/panel-elida-kd35t133: hold panel in reset for unprepare

[Jessica Zhang]

On 11/16/2023 7:17 AM, Chris Morgan wrote:
> On Wed, Nov 15, 2023 at 01:38:11PM -0800, Jessica Zhang wrote:
>>
>>
>> On 11/15/2023 7:26 AM, Chris Morgan wrote:
>>> From: Chris Morgan <macromorgan at hotmail.com>
>>>
>>> For devices like the Anbernic RG351M and RG351P the panel is wired to
>>> an always on regulator. When the device suspends and wakes up, there
>>> are some slight artifacts on the screen that go away over time. If
>>> instead we hold the panel in reset status after it is unprepared,
>>> this does not happen.
>>
>> Hi Chris,
>>
>> LGTM, though if this is fixing something maybe we can add
>>
>> Fixes: 5b6603360c12 ("drm/panel: add panel driver for Elida KD35T133
>> panels")
> 
> It *may* fix an intermittent issue with the panel resuming from
> suspend, but it really more solves an issue with devices for which
> we're still adding support.
> 
> Should I still tag it as a "fixes" then?

 From my understanding of the submitting patches docs [1], I think this 
warrants a "Fixes" since it's fixing an issue you're seeing with the 
original driver.

Thanks,

Jessica Zhang

[1] 
https://docs.kernel.org/process/submitting-patches.html#using-reported-by-tested-by-reviewed-by-suggested-by-and-fixes

> 
> Thank you.
> 
>>
>>>
>>> Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
>>
>> Reviewed-by: Jessica Zhang <quic_jesszhan at quicinc.com>
>>
>> Thanks,
>>
>> Jessica Zhang
>>
>>> ---
>>>    drivers/gpu/drm/panel/panel-elida-kd35t133.c | 2 ++
>>>    1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/panel/panel-elida-kd35t133.c b/drivers/gpu/drm/panel/panel-elida-kd35t133.c
>>> index 6cd8536c09ff..f1fc4a26f447 100644
>>> --- a/drivers/gpu/drm/panel/panel-elida-kd35t133.c
>>> +++ b/drivers/gpu/drm/panel/panel-elida-kd35t133.c
>>> @@ -104,6 +104,8 @@ static int kd35t133_unprepare(struct drm_panel *panel)
>>>    		return ret;
>>>    	}
>>> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
>>> +
>>>    	regulator_disable(ctx->iovcc);
>>>    	regulator_disable(ctx->vdd);
>>> -- 
>>> 2.34.1
>>>