iMac 10,1 with Ubuntu 16.04: black screen after suspend

[Alex Deucher]

On Fri, Jun 2, 2017 at 3:35 AM, Florian Echtler <floe at butterbrot.org> wrote:
> On 01.06.2017 19:53, Alex Deucher wrote:
>> On Thu, Jun 1, 2017 at 4:27 AM, Florian Echtler <floe at butterbrot.org> wrote:
>>> On 31.05.2017 14:57, Alex Deucher wrote:
>>>> On Wed, May 31, 2017 at 5:21 AM, Lukas Wunner <lukas at wunner.de> wrote:
>>>
>>> Here's the (substantial) dmesg output, with drm.debug=0xf:
>>> http://floe.butterbrot.org/external/radeon/dmesg_after_suspend
>>>
>>> I haven't been able to find any references to link training, though.
>>
>> I need your dmesg from boot to confirm the display topology, but eDP
>> with r7xx asics was pretty rare.  I suspect your system just uses
>> LVDS; as such there is no link training involved.
>
> I've updated the trace with increased log_buf_len so nothing is truncated:
>
> http://floe.butterbrot.org/external/radeon/dmesg_after_suspend.txt
>
> (trace now contains a full boot including suspend and wakeup)
>
> However, what I'm seeing now does sound like the internal connection is indeed eDP:
>
> [  166.816162] [drm:drm_mode_setcrtc] [CRTC:34:crtc-0]
> [  166.816166] [drm:drm_mode_setcrtc] [CONNECTOR:40:eDP-1]
> [  166.816167] [drm:drm_crtc_helper_set_config]
> [  166.816169] [drm:drm_crtc_helper_set_config] [CRTC:34:crtc-0] [FB:54]
> #connectors=1 (x y) (0 0)
> [  166.816170] [drm:drm_crtc_helper_set_config] crtc has no fb, full mode set
> [  166.816172] [drm:drm_mode_object_reference] OBJ ID: 40 (4)
> [  166.816173] [drm:drm_crtc_helper_set_config] encoder changed, full mode switch
> [  166.816174] [drm:drm_crtc_helper_set_config] crtc changed, full mode switch
> [  166.816174] [drm:drm_crtc_helper_set_config] [CONNECTOR:40:eDP-1] to
> [CRTC:34:crtc-0]
> [  166.816175] [drm:drm_crtc_helper_set_config] attempting to set mode from
> userspace
> [  166.816177] [drm:drm_mode_debug_printmodeline] Modeline 65:"" 0 241500 2560
> 2608 2640 2720 1440 1443 1448 1481 0x0 0x9
> [  166.816180] [drm:radeon_encoder_set_active_device] setting active device to
> 00000002 from 00000002 00000002 for encoder 3
> [  166.816183] [drm:radeon_get_monitor_bpc] eDP-1: Display bpc=8, returned bpc=8
> [  166.816185] [drm:drm_detect_monitor_audio] Monitor has basic audio support
> [  166.816186] [drm:radeon_get_monitor_bpc] eDP-1: Display bpc=8, returned bpc=8
> [  166.816188] [drm:drm_detect_monitor_audio] Monitor has basic audio support
> [  166.816192] [drm:drm_crtc_helper_set_mode] [CRTC:34:crtc-0]
> [  166.816208] [drm:radeon_get_monitor_bpc] eDP-1: Display bpc=8, returned bpc=8
> [  166.816210] [drm:radeon_atom_encoder_dpms] encoder dpms 30 to mode 3, devices
> 00000008, active_devices 00000000
> [  166.816213] [drm:radeon_atom_encoder_dpms] encoder dpms 22 to mode 3, devices
> 00000010, active_devices 00000000
> [  166.816235] [drm:drm_detect_monitor_audio] Monitor has basic audio support
> [  166.816237] [drm:radeon_compute_pll_avivo] 360000 - 360000, pll dividers -
> fb: 80.0 ref: 2, post 3
> [  166.824475] done.

Yes it is eDP:

[    3.197364] [drm] Radeon Display Connectors
[    3.197365] [drm] Connector 0:
[    3.197365] [drm]   DP-1
[    3.197366] [drm]   HPD1
[    3.197367] [drm]   DDC: 0x7e40 0x7e40 0x7e44 0x7e44 0x7e48 0x7e48
0x7e4c 0x7e4c
[    3.197367] [drm]   Encoders:
[    3.197368] [drm]     DFP1: INTERNAL_UNIPHY
[    3.197369] [drm] Connector 1:
[    3.197369] [drm]   eDP-1
[    3.197370] [drm]   HPD2
[    3.197371] [drm]   DDC: 0x7e50 0x7e50 0x7e54 0x7e54 0x7e58 0x7e58
0x7e5c 0x7e5c
[    3.197371] [drm]   Encoders:
[    3.197372] [drm]     LCD1: INTERNAL_UNIPHY
[    3.197372] [drm] Connector 2:
[    3.197372] [drm]   VGA-1
[    3.197373] [drm]   DDC: 0x7f10 0x7f10 0x7f14 0x7f14 0x7f18 0x7f18
0x7f1c 0x7f1c
[    3.197374] [drm]   Encoders:
[    3.197374] [drm]     CRT2: INTERNAL_KLDSCP_DAC2


>
> ... and a bit later:
>
> [  166.853787] [drm:radeon_dp_link_train_cr] clock recovery at voltage 0
> pre-emphasis 0
> [  166.853788] [drm:drm_detect_monitor_audio] Monitor has basic audio support
> [  166.855953] [drm:radeon_dp_link_train_ce] channel eq at voltage 0 pre-emphasis 0
>

Yes, the link training appears to complete fine.  I guess it's
something to do with the proprietary mux or backlight controls.

Alex

> Best, Florian
> --
> SENT FROM MY DEC VT50 TERMINAL
>