Created attachment 274089 [details] journalctl output for amdgpu When enabling AMDGPU Display Core for my Gigabyte RX 580, I get nothing more than a blank screen on my HDMI monitor.
Created attachment 274091 [details] journalctl output for drm
Comment on attachment 274091 [details] journalctl output for drm > Feb 10 17:33:47 valmar-desktop kernel: [drm] Cannot find any crtc or sizes This is the only error from the log.
Is there anything I can do to get any interest debug output?
Please attach your full dmesg output and xorg log if you are using X.
Created attachment 274115 [details] dmesg log
Created attachment 274117 [details] xorg log
Please capture dmesg again with amdgpu.dc_log=1 and drm.debug=6 kernel options. What monitor are you using? Is it connected via a dongle?
Created attachment 274131 [details] dmesg log with amdgpu.dc_log=1 and drm.debug=6 My monitor is an AOC I2379VHE. It's attached via a HDMI cable. What do you mean by dongle? Wifi?
(In reply to Kyle De'Vir from comment #8) > What do you mean by dongle? Wifi? A display dongle (e.g., DP to HDMI adapter).
Ah. None ~ just your average HDMI to HDMI cable.
Any progress on this issue? Are there any other logs or debugging output that I might be able to supply to help with this issue? If so, how do I acquire them?
It looks like we detect no display. We haven't yet had a chance to repro the problem. I'll see if I can find this display in the office. It'd be difficult debugging this remotely but if I can't repro this I might send you some extra logging patches in the hopes of getting more info.
Is there something that plain AMDGPU is doing that Display Core isn't, perhaps? Is there a way to find what the difference could be?
Created attachment 274477 [details] [PATCH] drm/amd/display: Disable HPD filter for HDMI This is a bit of a shot in the dark but I'm curious if HPD filtering causes us to lose the HPD signal for some reason. Do you have a chance to try this patch and see if it fixes the issue? Note: This patch is really only for debug purposes and might lead to other instability with display detection.
Am trying it out soon. Will try and capture dmesg log if it matters.
No change... dmesg looks no different. :/
Thanks for checking. Non-DC display driver and DC do detection somewhat differently. It's somewhat difficult to say what's going wrong there. Do you see different behavior when booting headless, then plugging in the display? If you're interested in debugging I'd probably use ftrace to get started, checking that the functions get hit: - handle_hpd_irq (only on hotplug) - dc_link_detect (crucial to detection) - dc_sink_create - dm_helpers_read_local_edid - drm_get_edid - dm_helpers_parse_edid_caps - amdgpu_dm_update_connector_after_detect - drm_mode_connector_update_edid_property Script to do ftrace debugging (run as root): #!/bin/bash cd /sys/kernel/debug/tracing/ echo handle_hpd_irq >> set_ftrace_filter echo dc_link_detect >> set_ftrace_filter echo dc_sink_create >> set_ftrace_filter echo dm_helpers_read_local_edid >> set_ftrace_filter echo drm_get_edid >> set_ftrace_filter echo dm_helpers_parse_edid_caps >> set_ftrace_filter echo amdgpu_dm_update_connector_after_detect >> set_ftrace_filter echo drm_mode_connector_update_edid_property >> set_ftrace_filter echo function_graph >> current_tracer echo '' >> trace cat trace_pipe
Actually, there was a change! Didn't have to boot headless at all, happily. Your patch didn't seem to change anything, but the update to 4.15.6 might have done something...? Did anything change for Display Core in the latest stable update?
I don't see any DC or other DRM change in the stable kernel between 4.15.5 and 4.15.6.
I'm going to test without your patch to see if the problem pops up again.
> I don't see any DC or other DRM change in the stable kernel between 4.15.5 > and 4.15.6. What about any of the other point releases? I tried without your patch, and amdgpu.dc=1 mysteriously just works... so strange that it just didn't before. I don't understand what even happened, and that's even more frustrating than it not working... urgh. :/
I think I have this exact same issue with my RX 580. When amdgpu.dc=1 is initialized at boot, the console goes blank as it thinks all displays are disconnected. Xorg is not able to enable the display either. With amdgpu.dc=0 all is fine. Tried with various (mostly Debian) kernels from 4.16 through 4.18~rc4, all have the issue. I'm building a 4.18~rc7 from kernel.org now to rule out Debian patches being the issue and will be able to provide logs. Should I open a new issue as this one has been closed? Or can this one be reopened?
(In reply to Claude Heiland-Allen from comment #22) > I think I have this exact same issue with my RX 580. When amdgpu.dc=1 is > initialized at boot, the console goes blank as it thinks all displays are > disconnected. Xorg is not able to enable the display either. With > amdgpu.dc=0 all is fine. Tried with various (mostly Debian) kernels from > 4.16 through 4.18~rc4, all have the issue. I'm building a 4.18~rc7 from > kernel.org now to rule out Debian patches being the issue and will be able > to provide logs. > > Should I open a new issue as this one has been closed? Or can this one be > reopened? Feel free to create a new ticket and include your dmesg and Xorg logs.