Comment 92 for bug 314928

Revision history for this message
Bryce Harrington (bryce) wrote : Re: [Bug 314928] Re: [i915GM] MTRR entry gets removed when restarting xorg - causes corruption on ttys

It's updated with a jaunty one now.

On Sat, Jun 06, 2009 at 09:20:41PM -0000, Giovanni Battista Salvietti wrote:
> I went to the ppa, but I see only a karmic repository.... where is the
> jaunty one?
>
> --
> [i915GM] MTRR entry gets removed when restarting xorg - causes corruption on ttys
> https://bugs.launchpad.net/bugs/314928
> You received this bug notification because you are a bug assignee.
>
> Status in X.org xf86-video-intel: In Progress
> Status in “linux” source package in Ubuntu: Fix Released
> Status in “xserver-xorg-video-intel” source package in Ubuntu: Fix Released
> Status in linux in Ubuntu Jaunty: In Progress
> Status in xserver-xorg-video-intel in Ubuntu Jaunty: In Progress
> Status in linux in Ubuntu Karmic: Fix Released
> Status in xserver-xorg-video-intel in Ubuntu Karmic: Fix Released
>
> Bug description:
> When comparing /proc/mtrr of intrepid and current jaunty i noticed there is an entry missing.
>
> Intrepid:
> reg00: base=0x00000000 ( 0MB), size=1024MB: write-back, count=1
> reg01: base=0x40000000 (1024MB), size= 512MB: write-back, count=1
> reg02: base=0x5f700000 (1527MB), size= 1MB: uncachable, count=1
> reg03: base=0x5f800000 (1528MB), size= 8MB: uncachable, count=1
> reg04: base=0xb0000000 (2816MB), size= 256MB: write-combining, count=1
>
> Jaunty:
> reg00: base=0x000000000 ( 0MB), size= 1024MB, count=1: write-back
> reg01: base=0x040000000 ( 1024MB), size= 512MB, count=1: write-back
> reg02: base=0x05f700000 ( 1527MB), size= 1MB, count=1: uncachable
> reg03: base=0x05f800000 ( 1528MB), size= 8MB, count=1: uncachable
>
> So I tried adding it back by using:
> sudo -s
> echo "base=0xb0000000 size=0x10000000 type=write-combining" > /proc/mtrr
>
> I have noticed a few things after adding that entry:
> - glxgears is now about twice as fast (I know its not a real benchmark ;)
> - 2D Performance does not seem affected however (just testing a bit with x11perf/gtkperf)
> - it fixes the corruption on the ttys (bug 312677)
>
> I also noticed that this entry gets removed everytime xorg gets restarted.
>
> But I'm not sure with all the recent changes in memory management if that entry should still be there or not.
>
> -------------
>
> lspci
> 00:00.0 Host bridge: Intel Corporation Mobile 915GM/PM/GMS/910GML Express Processor to DRAM Controller (rev 03)
> 00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03)
> 00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03)
> 00:1c.0 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 1 (rev 03)
> 00:1c.2 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 3 (rev 03)
> 00:1d.0 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 03)
> 00:1d.1 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 03)
> 00:1d.2 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 03)
> 00:1d.3 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 03)
> 00:1d.7 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 03)
> 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev d3)
> 00:1e.2 Multimedia audio controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) AC'97 Audio Controller (rev 03)
> 00:1e.3 Modem: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) AC'97 Modem Controller (rev 03)
> 00:1f.0 ISA bridge: Intel Corporation 82801FBM (ICH6M) LPC Interface Bridge (rev 03)
> 00:1f.2 IDE interface: Intel Corporation 82801FBM (ICH6M) SATA Controller (rev 03)
> 00:1f.3 SMBus: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) SMBus Controller (rev 03)
> 02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5751M Gigabit Ethernet PCI Express (rev 11)
> 04:00.0 CardBus bridge: Texas Instruments PCI4510 PC card Cardbus Controller (rev 03)
> 04:00.1 FireWire (IEEE 1394): Texas Instruments PCI4510 IEEE-1394 Controller (rev 01)
> 04:02.0 Network controller: Intel Corporation PRO/Wireless 2200BG [Calexico2] Network Connection (rev 05)