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: >>> On Wed, May 31, 2017 at 10:48:37AM +0200, Florian Echtler wrote: >>> >>> Hm, try booting with drm.debug=0xf to see if link training for the >>> eDP connector succeeds. If the link cannot be trained, it would >>> explain that the screen stays black. Should this indeed be the >>> case, one possible explanation would be that the panel is muxed >>> to the external port on resume and an appropriate command needs to >>> be sent to the SMC to switch the mux to the radeon card. This could >>> be done in the ->resume_early hook of your APP000C platform driver. >>> The apple-gmux driver contains something similar to power the discrete >>> GPU down if it was off before suspend (because the BIOS always powers >>> it up on resume). > > 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. Alex > >>> *shrug* Unfortunately I'm not familiar at all with radeontool. :-( >> >> You can use the radeonreg tool to dump the display registers: >> https://cgit.freedesktop.org/~agd5f/radeontool/ >> radeonreg regs dce3 >> replace dce3 with whatever dce version your card has. > > AFAICT the RV730 indeed has dce3, so I created a register dump before and after > suspend: > http://floe.butterbrot.org/external/radeon/regs_before_suspend.txt > http://floe.butterbrot.org/external/radeon/regs_after_suspend.txt > > The diff, however, is quite large, I have no idea which registers to look for. > > Best, Florian > -- > SENT FROM MY DEC VT50 TERMINAL >
