[PATCH 0/2] pwm: mtk-disp: Fix backlight configuration at boot

AngeloGioacchino Del Regno angelogioacchino.delregno at collabora.com
Wed Mar 8 08:04:54 PST 2023


Il 08/03/23 16:43, Greg Kroah-Hartman ha scritto:
> On Wed, Mar 08, 2023 at 03:55:59PM +0100, AngeloGioacchino Del Regno wrote:
>> Il 08/03/23 15:50, Greg Kroah-Hartman ha scritto:
>>> On Wed, Mar 08, 2023 at 12:46:07PM +0100, AngeloGioacchino Del Regno wrote:
>>>> Il 23/02/23 15:16, AngeloGioacchino Del Regno ha scritto:
>>>>> Il 23/01/23 17:06, AngeloGioacchino Del Regno ha scritto:
>>>>>> Since the pwm-mtk-disp driver was fixed to get PWM_EN state from the
>>>>>> right register, an old two-wrongs-make-one-right issue emerged: as a
>>>>>> result, MT8192 Asurada Spherion got no backlight at boot unless a
>>>>>> suspend/resume cycle was performed.
>>>>>> Also, the backlight would sometimes not get updated with the requested
>>>>>> value, requiring the user to change it back and forth until it worked.
>>>>>>
>>>>>> This series fixes both of the aforementioned issues found on MT8192.
>>>>>>
>>>>>> AngeloGioacchino Del Regno (2):
>>>>>>      pwm: mtk-disp: Disable shadow registers before setting backlight
>>>>>>        values
>>>>>>      pwm: mtk-disp: Configure double buffering before reading in
>>>>>>        .get_state()
>>>>>>
>>>>>>     drivers/pwm/pwm-mtk-disp.c | 34 +++++++++++++++++++++++-----------
>>>>>>     1 file changed, 23 insertions(+), 11 deletions(-)
>>>>>>
>>>>>
>>>>> Gentle ping for this one: this is fixing backlight issues on multiple MediaTek
>>>>> SoCs and was well tested.
>>>>>
>>>>> Thanks,
>>>>> Angelo
>>>>
>>>> Since this series was sent more than one month ago, and since this fixes broken
>>>> backlight on a number of Chromebooks with MT8183 and MT8192 SoCs, and seen the
>>>> urgency of getting these fixes in, I'm adding Greg to the loop.
>>>
>>> $ ./scripts/get_maintainer.pl drivers/pwm/pwm-mtk-disp.c
>>> Thierry Reding <thierry.reding at gmail.com> (maintainer:PWM SUBSYSTEM)
>>> "Uwe Kleine-König" <u.kleine-koenig at pengutronix.de> (reviewer:PWM SUBSYSTEM)
>>> Matthias Brugger <matthias.bgg at gmail.com> (maintainer:ARM/Mediatek SoC support)
>>> AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com> (reviewer:ARM/Mediatek SoC support)
>>> linux-pwm at vger.kernel.org (open list:PWM SUBSYSTEM)
>>> linux-kernel at vger.kernel.org (open list:ARM/Mediatek SoC support)
>>> linux-arm-kernel at lists.infradead.org (moderated list:ARM/Mediatek SoC support)
>>> linux-mediatek at lists.infradead.org (moderated list:ARM/Mediatek SoC support)
>>>
>>> I don't see my name in there, did I become the PWM maintainer somehow?
>>>
>>> What's wrong with Thierry taking this like normal?
>>>
>>
>> Nothing wrong with that. I felt like this series got ignored as I've never
>> received any reply from Thierry, even though it's a Fixes series that I deem
>> to be moderately urgent; that's why I added you to the loop.
> 
> Then ask Thierry and Uwe, what would you want to have happen if you were
> the maintainer of a subsystem?
> 
>> If that created unnecessary noise, I'm extremely sorry and won't happen again.
> 
> Not noise, just confusion on my part.  I'm glad to take patches that
> have no obvious maintainers, or maintainers that have disappeared, but
> that doesn't seem to be the case here.
> 
> Also remember that we had the merge window, which is 2 weeks of us not
> being able to take any new code at all, even for fixes.
> 
> And finally, to make it easier for your code to be accepted, please take
> the time to review other's code for the subsystems you care about to
> make the maintainer's load easier.  If you do that, you will often find
> your patches getting faster response just by virtue of there being less
> work to do on the subsystem overall.  Why not do that right now to help
> out with other PWM patches?
> 
> thanks,
> 
> greg k-h
> 

That's right, I see the point. Will try to help as soon as I can find BW.

Thanks and sorry again,
Angelo




More information about the Linux-mediatek mailing list