[PATCH] drm: Fix HDMI_STATIC_METADATA_TYPE1 constant.

[Mario Kleiner]

Ping! Anybody wanna review the most trivial, obviously correct, and
non-intrusive patch ever to fix a real bug? The Kodi devs changed their
broken constant and as if by magic, some LG TV now has working HDR support,
so we now know the constant is actually expected to be correct by at least
some real display hw out there.

thanks,
-mario


On Mon, Jan 25, 2021 at 8:53 PM Mario Kleiner <mario.kleiner.de at gmail.com>
wrote:

>
>
> On Mon, Jan 25, 2021 at 5:05 PM Simon Ser <contact at emersion.fr> wrote:
>
>> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
>>
>> On Monday, January 25th, 2021 at 5:00 PM, Mario Kleiner <
>> mario.kleiner.de at gmail.com> wrote:
>>
>> > On Mon, Jan 25, 2021 at 1:14 PM Simon Ser <contact at emersion.fr> wrote:
>> >
>> > > > This is not an uapi defintion anyway so fixing should be fine.
>> > >
>> > > Oh, my bad, I thought this was in drm_mode.h, but it's not. Then yeah
>> > >
>> > > should be completely fine to fix it.
>> >
>> > Good! The beginning of the end of a sad story ;). So i guess i can
>> > get your r-b's for it?
>>
>> Sorry, I haven't verified that this wouldn't break the world, so I'm
>> not comfortable giving a R-b.
>>
>>
> Breaking the world is pretty unlikely for an unused #define, but I
> understand.
>
> I guess Ville will have access to the relevant spec to verify: It is the
> CTA-861-G spec, table 44 in section 6.9 and also specifically section 6.9.1.
>
>
>> > Will this fix propagate into igt and libdrm? Or are separate fixup
>> patches needed?
>>
>> No, since this is not part of UAPI.
>>
>
> Ok. I'll submit patches once this one landed in the kernel.
>
>
>>
>> > Simon, could you let the Kodi devs know in case you have a line to
>> > them? I didn't know that there is even one more real-world HDR client
>> > for Linux, apart from AMD's amdvlk Vulkan driver, which does things
>> > right and doesn't need fixing.
>>
>> Seems like Kodi hardcodes the bad version:
>>
>>
>> https://github.com/xbmc/xbmc/blob/aa5c2e79c069ba7d0ab1d8ad930e4294bf554680/xbmc/cores/VideoPlayer/Buffers/VideoBufferDRMPRIME.h#L24
>>
>>
> Thanks. I've filed an issue to them under:
>
> https://github.com/xbmc/xbmc/issues/19122
>
>
>> Maybe we should add the good version in UAPI header?
>>
>
> I'm scared that future HDR definitions would be as carefully done and
> reviewed as this one, given how much harder it would be to fix them :/
> But maybe that's just exhausted me who spent too many weeks dealing with
> HDR bugs everywhere.
>
> -mario
>
>
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