On 08/27/2012 03:08 PM, Daniel Vetter wrote: > On Mon, Aug 27, 2012 at 02:47:58PM -0400, Chun-Yu Shei wrote: >> On 8/15/2012 6:47 PM, Daniel Vetter wrote: >>> On Wed, Aug 15, 2012 at 06:38:10PM -0400, Chun-Yu Shei wrote: >>>> Hi, >>>> >>>> I recently upgraded to a 27" monitor (2560x1440) from a 23" one >>>> (1920x1080), and had to switch to Windows because the new monitor is >>>> unusable in Linux. Today, about a month later, I decided to give >>>> Linux another try, since there have been several updates to the >>>> Intel graphics driver since then. >>>> >>>> Unfortunately, it seems that it's still unusable with >>>> xf86-video-intel 2.20.3 -- after a little while, the video signal to >>>> the 27" monitor completely stops, and it goes into power saving >>>> mode. I'm running dual monitors with the old 23", and that one >>>> continues running fine when this happens. This happens on my >>>> ThinkPad X220 (i5-2540M). The 27" is connected via DisplayPort, and >>>> the 23" via DVI. SNA is enabled, if it makes any difference (I >>>> haven't tried turning it off, but I probably should). This is the >>>> biggest problem I'm facing when it comes to Linux support. >>>> >>>> I also gave the new "TearFree" option a try, and while it does a >>>> great job of eliminating tearing, it makes the two monitors become >>>> mirrors of each other for some reason. If I take a screenshot with >>>> the GNOME tool, the screenshot comes out as expected (unmirrored), >>>> but the video output on the two monitors is mirrored in reality. >>>> Disabling "TearFree" fixes this. >>>> >>>> Also, when I'm using the ThinkPad's built-in display, it sometimes >>>> turns off for no apparent reason, although it's not too big of a >>>> deal since a suspend/resume cycle seems to fix things (and I haven't >>>> used 2.20.3 long enough to experience this yet). >>>> >>>> Any ideas/things I can do to help track these issues down? >>> >>> For the screen blanking issues, the kernel is the important part. Please >>> boot with drm.debug=0xe added to your kernel bootline and grab the full >>> dmesg. >>> -Daniel >>> >> >> OK, I finally got around to doing this... I just upgraded to the >> 3.5.3 kernel and xf86-video-intel 2.20.5 as well. >> >> Here's the initial dmesg upon bootup: http://pastebin.com/41F2AA0f >> >> And here's the dmesg right after the 27" goes blank: >> http://pastebin.com/3CTRETQ4 (not completely blank, though... there >> are a few lines at the very left & top edge of the display) >> >> A few seconds later, the display came back, and here's the dmesg >> right after that: http://pastebin.com/9mdfY5P1 > > Hm, there's nothing really interesting with that screen going on ... Also, > 3.5.3 is up-to-date with all recent DP fixes. One thing that could be is > that this is another version of our fdi link training woes on ivb. > > To check for that, can you please run your 27" screen at a much lower > resolution? If it still blanks out, it's a different issue. > > Thanks, Daniel > Seems to be working perfectly at 1600x900 (btw, I'm on Sandy Bridge, not ivb). Chun-Yu
