Hi, I've heard that you need users having the RC6 bug. I have the following setup: CPU: Intel Core i5-2500K Mainboard: ASRock Z68 Pro3-M Memory: Corsair Vengeance CMZ8GX3M2A1866C9 Although the CPU doesn't support VT-d, I disabled all virtualization support in the UEFI setup. I use Arch Linux and Gnome 3 in the fallback mode. The problem is more drastic without fallback mode, however. Whenever I enable RC6, I get the a few of these errors in dmesg: [ 48.900000] WARNING: at drivers/gpu/drm/i915/i915_drv.c:387 __gen6_gt_wait_for_fifo+0x94/0xa0 [i915]() [ 48.900002] Hardware name: To Be Filled By O.E.M. [ 48.900002] Modules linked in: ipv6 fuse ext2 snd_hda_codec_hdmi snd_hda_codec_realtek mei(C) joydev r8169 shpchp pci_hotplug usbhid hid snd_hda_intel iTCO_wdt mii iTCO_vendor_support i2c_i801 snd_hda_codec processor snd_hwdep snd_pcm snd_timer snd soundcore snd_page_alloc psmouse serio_raw pcspkr evdev ext4 mbcache jbd2 crc16 xhci_hcd ehci_hcd usbcore i915 drm_kms_helper drm intel_agp i2c_algo_bit button intel_gtt i2c_core video sd_mod ahci libahci libata scsi_mod [ 48.900019] Pid: 623, comm: Xorg Tainted: G WC 3.1.9-2-ARCH #1 [ 48.900020] Call Trace: [ 48.900023] [<ffffffff81061bef>] warn_slowpath_common+0x7f/0xc0 [ 48.900025] [<ffffffff81061c4a>] warn_slowpath_null+0x1a/0x20 [ 48.900028] [<ffffffffa00e0764>] __gen6_gt_wait_for_fifo+0x94/0xa0 [i915] [ 48.900032] [<ffffffffa015d2d5>] ring_write_tail+0x65/0x120 [i915] [ 48.900036] [<ffffffffa01619bc>] render_ring_flush+0xbc/0xe0 [i915] [ 48.900040] [<ffffffffa010b803>] i915_gem_flush_ring+0x43/0x250 [i915] [ 48.900044] [<ffffffffa0112b50>] i915_gem_do_execbuffer.isra.7+0x1020/0x16d0 [i915] [ 48.900048] [<ffffffffa01136bb>] i915_gem_execbuffer2+0x8b/0x240 [i915] [ 48.900051] [<ffffffffa0098434>] drm_ioctl+0x3e4/0x4c0 [drm] [ 48.900053] [<ffffffff810746cb>] ? recalc_sigpending+0x1b/0x50 [ 48.900057] [<ffffffffa0113630>] ? i915_gem_execbuffer+0x430/0x430 [i915] [ 48.900059] [<ffffffff8101e9b1>] ? fpu_finit+0x21/0x40 [ 48.900061] [<ffffffff8116fddf>] do_vfs_ioctl+0x8f/0x500 [ 48.900063] [<ffffffff81014beb>] ? sys_rt_sigreturn+0x1eb/0x200 [ 48.900064] [<ffffffff811702e1>] sys_ioctl+0x91/0xa0 [ 48.900066] [<ffffffff8140c3c2>] system_call_fastpath+0x16/0x1b [ 48.900067] ---[ end trace 9a23b8b32b16a424 ]--- and then [ 53.163526] [drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung [ 53.165046] [drm] capturing error event; look for more information in /debug/dri/0/i915_error_state [ 53.177356] [drm:i915_wait_request] *ERROR* i915_wait_request returns -11 (awaiting 1593 at 1592, next 1594) [ 53.181979] [drm:init_ring_common] *ERROR* render ring initialization failed ctl 00000000 head 00000000 tail 00000000 start 00000000 [ 53.185522] [drm:init_ring_common] *ERROR* gen6 bsd ring initialization failed ctl 00000000 head 00000000 tail 00000000 start 00000000 [ 53.188558] [drm:init_ring_common] *ERROR* blt ring initialization failed ctl 00000000 head 00000000 tail 00000000 start 00000000 [ 55.330146] [drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung [ 55.332202] [drm:i915_wait_request] *ERROR* i915_wait_request returns -11 (awaiting 1594 at 1591, next 1595) [ 55.333258] [drm:i915_reset] *ERROR* GPU hanging too fast, declaring wedged! [ 55.333260] [drm:i915_reset] *ERROR* Failed to reset chip. Of course, I'd be willing to test out stuff. I'd need a bit of guide, however. -CC -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.freedesktop.org/archives/intel-gfx/attachments/20120116/20df9d7f/attachment-0001.htm>