arrandale/5 series intel graphics on lenovo t410s requires "intel_iommu=igfx_off" with precise/3.2 kernel

[Roland Dreier]

Using the latest default precise kernel on my Lenovo T410s laptop with Intel integrated graphics ends up with a bunch of messages like

[ 98.467011] DRHD: handling fault status reg 2
[ 98.467014] DMAR:[DMA Write] Request device [00:02.0] fault addr 400020000
[ 98.467038] DMAR:[fault reason 05] PTE Write access is not set

in the kernel log, and graphics seem pretty choppy. Booting with "intel_iommu=igfx_off" makes this go away.

I see that I have the calpella device that the quirk in drivers/iommu/intel-iommu.c keys off of:

$ lspci -nn -d 8086:0044
00:00.0 Host bridge [0600]: Intel Corporation Core Processor DRAM Controller [8086:0044] (rev 02)

but in that quirk:

static void __devinit quirk_calpella_no_shadow_gtt(struct pci_dev *dev)
{
        unsigned short ggc;

        if (pci_read_config_word(dev, GGC, &ggc))
                return;

        if (!(ggc & GGC_MEMORY_VT_ENABLED)) {
                printk(KERN_INFO "DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics\n");
                dmar_map_gfx = 0;
        } else if (dmar_map_gfx) {
                /* we have to ensure the gfx device is idle before we flush */
                printk(KERN_INFO "DMAR: Disabling batched IOTLB flush on Ironlake\n");
                intel_iommu_strict = 1;
       }
}

the first test apparently ends up as false, and I just see

[ 0.808010] DMAR: Disabling batched IOTLB flush on Ironlake

in my kernel log, which is apparently not sufficient to make things actually work.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-7-generic 3.2.0-7.13
ProcVersionSignature: Ubuntu 3.2.0-7.13-generic 3.2.0-rc7
Uname: Linux 3.2.0-7-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 1.90-0ubuntu1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: roland 2095 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf2520000 irq 47'
   Mixer name : 'Intel IbexPeak HDMI'
   Components : 'HDA:14f15069,17aa21a4,00100302 HDA:80862804,17aa21b5,00100000'
   Controls : 23
   Simple ctrls : 8
Card1.Amixer.info:
 Card hw:1 'CODEC'/'Burr-Brown from TI USB Audio CODEC at usb-0000:00:1a.0-1.5.2.2, full speed'
   Mixer name : 'USB Mixer'
   Components : 'USB08bb:2900'
   Controls : 2
   Simple ctrls : 1
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw 6UHT31WW-1.12'
   Mixer name : 'ThinkPad EC 6UHT31WW-1.12'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Thu Jan 5 09:30:56 2012
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120104)
MachineType: LENOVO 2901CTO
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-7-generic root=UUID=677292b2-a7ba-4d9e-8f1a-662c546b62ce ro intel_iommu=igfx_off quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.2.0-7-generic N/A
 linux-backports-modules-3.2.0-7-generic N/A
 linux-firmware 1.67
SourcePackage: linux
StagingDrivers: mei
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:

dmi.bios.date: 10/27/2010
dmi.bios.vendor: LENOVO
dmi.bios.version: 6UET61WW (1.41 )
dmi.board.name: 2901CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6UET61WW(1.41):bd10/27/2010:svnLENOVO:pn2901CTO:pvrThinkPadT410s:rvnLENOVO:rn2901CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2901CTO
dmi.product.version: ThinkPad T410s
dmi.sys.vendor: LENOVO

[Joseph Salisbury (jsalisbury)]

This appears to be a duplicate of bug 911236