Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?
		The problem becomes apparent for example if I start chromium and try to move the whole browser window by holding down the alt key + the mouse, resulting in almost slow motion.
		Similar effects with Iceweasel on various websites e.g. googlemaps. This is after a fresh reboot.
		Furthermore I noticed after a couple of resumes I can't play videos with the default settings any more, e.g. in mplayer only with the -xv X11 option.
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
		I switched from testing to experimental (xserver-xorg-video-intel 2:2.99.917-1~bpo8+1) both with "uxa" acceleration in /etc/X11/xorg.conf.d/20-intel.conf as follows:
		Section "Device"
			  Identifier  "Intel Graphics"
				Driver      "intel"
				Option      "AccelMethod"  "uxa"
		EndSection
   * What was the outcome of this action?
		Slightly better performance but the issue still remains, especially the loss of the acceleration after resumes.
	 * What outcome did you expect instead?
		No loss of the hardware acceleration

Does that also happen with a newer kernel and/or mesa?

Cheers,
Julien

Hi,

thanks for you indication! I tried it with mesa, ending up with an
unusable screen rendering only artefacts after resume.

I updated & upgraded recently and therefore should use the latest
available kernel on testing(3.16.0-4-amd64). I was just wondering how to
install a newer/other kernel without messing my sources?

I found my dmesg outputs the following lines:
[32174.108381] [drm] stuck on render ring
[32174.110149] [drm] GPU HANG: ecode 0:0x00dfffff, reason: Ring hung,
action: reset

& stumbled across this guy reporting similar issues with intel graphic
driver on debian: http://www.moi.vonos.net/2015/05/t550-linux/

best,
Olsen

Just to paste some more info, when I start chromium after resume the
screen's black and dmesg output's as follows:

...
[38088.042961] [drm] stuck on render ring
[38088.043945] [drm] GPU HANG: ecode 0:0x00dfffff, reason: Ring hung,
action: reset
[38090.045530] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off
[42163.120279] [drm] stuck on render ring
[42163.121450] [drm] GPU HANG: ecode 0:0x00dfffff, in chromium [9505],
reason: Ring hung, action: reset
[42165.122279] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off
[42169.126284] [drm] stuck on render ring
[42169.127978] [drm] GPU HANG: ecode 0:0xf3cffffe, in chromium [9505],
reason: Ring hung, action: reset
[42171.128257] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off
...