4K @ 60Hz over HDMI 2.0 not working with AMDGPU-DAL

💬 Alex Deucher @agd5f said:

Is the issue that a 60 hz mode is not available or that a 60 hz mode does not work? Please attach your xorg log, dmesg output and xrandr output. You may need this drm patch:
https://lists.freedesktop.org/archives/dri-devel/2016-May/107463.html

💬 Harry Wentland @hwentland said:

I don't have the same monitor but I don't have any problem lighting up with HDMI 2.0 4k 60Hz with Alex's amd-staging-4.7 and the commit from a week ago:

commit 4fa58023f62a95e93f82a25cdceb87b19b69b27f
Author: Christian König christian.koenig@amd.com
Date: Mon Oct 17 15:34:07 2016 +0200

reservation: revert "wait only with non-zero timeout specified (v3)"

This reverts commit fb8b7d2b9d80e1e71f379e57355936bd2b024be9.

Otherwise signaling might never be activated on the fences. This can
result in infinite waiting with hardware which has unreliable interrupts.

Signed-off-by: Christian König christian.koenig@amd.com
Reviewed-by: Chunming Zhou david1.zhou@amd.com

If you still see this issue please attach xorg log, dmesg and xrandr output, as Alex suggested.

📎 Dillon Dixon uploaded an attachment:

Attachment 127712, "xrandr, dmesg, and xorg logs":
amdgpu_logs.zip

💬 Dillon Dixon said:

Thanks for responding to my ticket! Sorry, I didn't have time to record down all the relevant information until recently.

Anyway, the 60 Hz mode is missing completely. I attached the relevant logs to the ticket.

I tried updating my clone of the kernel repo up to the commit at the end of this post, but the issue persists. I will try the suggested patch and respond as to whether or not it makes a difference for me.

Thanks again!

commit 019b84cce0585498430215503a50633d2d6a7fc8
Author: Alex Deucher alexander.deucher@amd.com
Date: Wed Oct 26 16:41:39 2016 -0400

drm/amdgpu: add support for new smc firmware on tonga

Newer tonga parts require new smc firmware.

Reviewed-by: Eric Huang JinHuiEric.Huang@amd.com
Signed-off-by: Alex Deucher alexander.deucher@amd.com
Cc: stable@vger.kernel.org

💬 Dillon Dixon said:

Just tried the patch. That added a 60 Hz mode back in, but when I try to switch to it, I get no signal.

I can post logs if relevant.

Here is my output now from xrandr:

Screen 0: minimum 320 x 200, current 3840 x 2160, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
DisplayPort-2 disconnected (normal left inverted right x axis y axis)
HDMI-A-0 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 878mm x 485mm
3840x2160 30.00*+ 59.94 59.88 24.00 29.97 23.98 29.94 23.95
4096x2160 59.94 59.88 24.00 29.97 23.98 29.94 23.95
1920x1200 30.00
1920x1080 120.04 120.00 119.88 60.00 59.94 24.00 23.98
1600x1200 30.00
1680x1050 30.00
1280x1024 30.00
1440x900 30.00
1280x800 30.00
1280x720 60.00 59.94
1024x768 30.00
800x600 30.00
720x480 60.00 59.94
640x480 60.00 59.94

💬 Dillon Dixon said:

I was reminded today that this TV is a bit strange in that 4K @ 60 Hz only works with 4:2:0 chroma, while the common expectation would perhaps be 4:4:4. Perhaps that can help lead to a solution?

💬 John Bridgman @jbridgman said:

The NVidia ticket suggests this might be an EDID issue, with the display saying that it supports 4:2:2 at 4K/60 Hz when in fact it only supports 4:2:0.

Or could have been an NVidia driver bug that caused problems when modes for both 4:2:2 and 4:2:0 were available, hard to say. Anyways, seems like if we can get the driver to try 4:2:0 (possibly ignoring the monitor to do so) then it should work at 60 Hz.