LinuxLists.cc - [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

2021-05-19 19:29:12

Subject: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

Another Samsung OLED panel needs DPCD to get control of backlight.
Kernel 5.12+ support the backlight via:
commit: <4a8d79901d5b> ("drm/i915/dp: Enable Intel's HDR backlight interface (only SDR for now)")
Only make backlight work on lower versions of kernel.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3474
Cc: [email protected] # 5.11-
Signed-off-by: Aaron Ma <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 5bd0934004e3..7b91d8a76cd6 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1960,6 +1960,7 @@ static const struct edid_quirk edid_quirk_list[] = {
{ MFG(0x4d, 0x10), PROD_ID(0xe6, 0x14), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
{ MFG(0x4c, 0x83), PROD_ID(0x47, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
{ MFG(0x09, 0xe5), PROD_ID(0xde, 0x08), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
+ { MFG(0x4c, 0x83), PROD_ID(0x57, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
};

#undef MFG
--
2.25.1

2021-05-19 20:16:47

by Lyude Paul

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Subject: Re: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

Seems reasonable to me:

Reviewed-by: Lyude Paul <[email protected]>

On Wed, 2021-05-19 at 17:53 +0800, Aaron Ma wrote:
> Another Samsung OLED panel needs DPCD to get control of backlight.
> Kernel 5.12+ support the backlight via:
> commit: <4a8d79901d5b> ("drm/i915/dp: Enable Intel's HDR backlight interface
> (only SDR for now)")
> Only make backlight work on lower versions of kernel.
>
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3474
> Cc: [email protected] # 5.11-
> Signed-off-by: Aaron Ma <[email protected]>
> ---
> drivers/gpu/drm/drm_dp_helper.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 5bd0934004e3..7b91d8a76cd6 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -1960,6 +1960,7 @@ static const struct edid_quirk edid_quirk_list[] = {
>         { MFG(0x4d, 0x10), PROD_ID(0xe6, 0x14),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>         { MFG(0x4c, 0x83), PROD_ID(0x47, 0x41),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>         { MFG(0x09, 0xe5), PROD_ID(0xde, 0x08),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
> +       { MFG(0x4c, 0x83), PROD_ID(0x57, 0x41),
> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
> };
>
> #undef MFG

--
Sincerely,
Lyude Paul (she/her)
Software Engineer at Red Hat

Note: I deal with a lot of emails and have a lot of bugs on my plate. If you've
asked me a question, are waiting for a review/merge on a patch, etc. and I
haven't responded in a while, please feel free to send me another email to check
on my status. I don't bite!

2021-06-30 04:56:18

by Aaron Ma

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Subject: Re: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

Hi Greg:

Could this patch get a chance to be applied on stable kernel?
It only for 5.11- kernel, not for Linus' tree.

Thanks,
Aaron

On 5/20/21 12:27 AM, Lyude Paul wrote:
> Seems reasonable to me:
>
> Reviewed-by: Lyude Paul <[email protected]>
>
> On Wed, 2021-05-19 at 17:53 +0800, Aaron Ma wrote:
>> Another Samsung OLED panel needs DPCD to get control of backlight.
>> Kernel 5.12+ support the backlight via:
>> commit: <4a8d79901d5b> ("drm/i915/dp: Enable Intel's HDR backlight interface
>> (only SDR for now)")
>> Only make backlight work on lower versions of kernel.
>>
>> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3474
>> Cc: [email protected] # 5.11-
>> Signed-off-by: Aaron Ma <[email protected]>
>> ---
>> drivers/gpu/drm/drm_dp_helper.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
>> index 5bd0934004e3..7b91d8a76cd6 100644
>> --- a/drivers/gpu/drm/drm_dp_helper.c
>> +++ b/drivers/gpu/drm/drm_dp_helper.c
>> @@ -1960,6 +1960,7 @@ static const struct edid_quirk edid_quirk_list[] = {
>>         { MFG(0x4d, 0x10), PROD_ID(0xe6, 0x14),
>> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>>         { MFG(0x4c, 0x83), PROD_ID(0x47, 0x41),
>> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>>         { MFG(0x09, 0xe5), PROD_ID(0xde, 0x08),
>> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>> +       { MFG(0x4c, 0x83), PROD_ID(0x57, 0x41),
>> BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
>> };
>>
>> #undef MFG

2021-06-30 09:06:21

by Greg Kroah-Hartman

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Subject: Re: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

On Wed, Jun 30, 2021 at 12:29:05PM +0800, Aaron Ma wrote:
> Hi Greg:
>
> Could this patch get a chance to be applied on stable kernel?
> It only for 5.11- kernel, not for Linus' tree.

What is the git commit id for it in Linus's tree?

And if this is not for Linus's tree, please resubmit it and document the
heck out of why it is not valid for Linus's tree and exactly what stable
trees you want this applied to (hint, 5.11 is long end-of-life and 5.12
only has about 1-2 more weeks left...)

thanks,

greg k-h

2021-06-30 09:40:06

by Aaron Ma

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Subject: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

Subject: Re: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

Subject: Re: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

Subject: Re: [PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel

Subject: [RESEND][PATCH] drm/i915: Force DPCD backlight mode for Samsung 16727 panel