amdgpu 4k at 120Hz / HDMI 2.1

[Armin Wolf]

Am 09.01.25 um 10:19 schrieb Mischa Baars:
> On Mon, Jan 6, 2025 at 4:30 AM Mario Limonciello
> <mario.limonciello at amd.com> wrote:
>
>> When new specifications are made available it's not like the old one
>> suddenly becomes "open", so I don't see any reason that a new
>> specification would change anything.
> I paid about €3000 for my new PC, including €300 for the graphics card
> with HDMI 2.1 output and about €2000 for my new Samsung OLED TV with 4
> HDMI 2.1 inputs, and now you are telling me that I will not be able to
> utilize them fully because the cable specification has not been made
> publicly available?
>
> Did someone forget to pay the people that design the cables? Because
> that is what it sounds like. Why does Linux stay behind?

Sadly the HDMI forum only provides the HDMI specification under a special license which
prohibits implementing it in open source drivers.

Since membership inside the HDMI forum costs 15000$ annually, i suspect that the HDMI forum
is abusing its power to force people to join (and pay).

I can feel your disappointment, but there is nothing we can do which does not land us in court :(.

Thanks,
Armin Wolf

> On Mon, Jan 6, 2025 at 4:41 PM Michel Dänzer <michel.daenzer at mailbox.org> wrote:
>> On 2024-12-31 13:42, Mischa Baars wrote:
>>> In the meantime I also checked the framerate synchronization through
>>> glxgears at different resolutions and framerates. This does function
>>> as expected. Although I haven't yet inspected the glxgears source
>>> codes in detail, the OpenGL double buffering must be functional up to
>>> some level. This means that the problem must be confined to GTK and
>>> the GtkGLArea widget. Using GDK_BACKEND=x11 I do get a double buffered
>>> context, but the default buffer does not alternate between GL_FRONT
>>> and GL_BACK.
>> Yeah, that's not how double-buffering works in GL. The draw buffer is always GL_BACK, SwapBuffers doesn't affect that (it just may internally change which actual buffer GL_BACK refers to).
>>
>> I don't see more context about the issue you're investigating, any pointers?
>>
>>
>> --
>> Earthling Michel Dänzer       \        GNOME / Xwayland / Mesa developer
>> https://redhat.com             \               Libre software enthusiast