On 30.05.2017 12:54, Lukas Wunner wrote: > On Tue, May 30, 2017 at 11:34:17AM +0200, Florian Echtler wrote: >> On 26.05.2017 23:03, Lukas Wunner wrote: >>> On Fri, May 26, 2017 at 02:13:29PM +0200, Florian Echtler wrote: >>>> I'm running Ubuntu 16.04.2 on a 27" unibody iMac 10,1 from 2009. However, even >>>> with the most recent HWE stack (kernel 4.8), the display stays black after >>>> suspend. I can ssh into the machine, so wakeup is OK, but the display is >>>> entirely black (backlight stays off). > > So, just to confirm, if you never plug in an external DP source and the iMac > comes out of sleep, the display stays black? Correct, verified this just now. > If you log in via ssh and look at dmesg, was radeon able to train the DP > link again? No error messages, nothing? Here are the relevant dmesg lines after wakeup: [ 157.622950] [drm] enabling PCIE gen 2 link speeds, disable with radeon.pcie_gen2=0 [ 157.626077] [drm] PCIE GART of 1024M enabled (table at 0x000000000014C000). [ 157.626094] radeon 0000:02:00.0: WB enabled [ 157.626097] radeon 0000:02:00.0: fence driver on ring 0 use gpu addr 0x0000000010000c00 and cpu addr 0xffffa1242dfd6c00 [ 157.626098] radeon 0000:02:00.0: fence driver on ring 3 use gpu addr 0x0000000010000c0c and cpu addr 0xffffa1242dfd6c0c [ 157.626315] radeon 0000:02:00.0: fence driver on ring 5 use gpu addr 0x000000000005c598 and cpu addr 0xffffbc3081c1c598 [ 157.672183] [drm] ring test on 0 succeeded in 1 usecs [ 157.672187] [drm] ring test on 3 succeeded in 2 usecs [ 157.847098] [drm] ring test on 5 succeeded in 1 usecs [ 157.847102] [drm] UVD initialized successfully. [ 157.847121] [drm] ib test on ring 0 succeeded in 0 usecs [ 157.847136] [drm] ib test on ring 3 succeeded in 0 usecs [ 158.524061] [drm] ib test on ring 5 succeeded And this is logged in Xorg.0.log after wakeup: [ 229.956] (II) RADEON(0): Allocate new frame buffer 320x200 stride 384 [ 229.956] (II) RADEON(0): VRAM usage limit set to 219596K xrandr still shows the eDP output as connected and active with 2560x1440 resolution. > Is the panel off or is it on but merely with 0% brightness? The backlight is definitely off. I've tried to shine a torch onto the panel and see if any content is visible, but it looks like the panel itself is off, too. > There's a block of pins on the GPU for "system management" which contains > a bunch of GPIO, OEM and reserved pins. Three of these are used to control > the panel when it's switched to the radeon card: > pin 23 PNL_PWR_EN > pin 25 PNL_BL_EN > pin 27 PNL_BL_PWM > > Basically you'd need to know what these are set to before and after sleep. > I don't know how to access them, presumably via a BAR register. A quick > look at the RV730-specific registers in drivers/gpu/drm/radeon/*.h did not > yield anything useful, but someone at AMD may be able to find this out. Can I perhaps use radeontool for this? I.e. dump registers before and after sleep and see if there's a difference? Or is radeontool too old to know about the correct registers? Best, Florian -- SENT FROM MY DEC VT50 TERMINAL
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