i915 kernel warning

[Daniel Vetter]

On Wed, Aug 06, 2014 at 10:03:46PM +0300, Mihai Donțu wrote:
> Hi,
> 
> This just happened to me:
> 
> Aug  6 21:37:37 mdontu-l kernel: ------------[ cut here ]------------
> Aug  6 21:37:37 mdontu-l kernel: WARNING: CPU: 3 PID: 4823 at drivers/gpu/drm/i915/intel_display.c:3313 intel_crtc_wait_for_pending_flips+0x16c/0x180()
> Aug  6 21:37:37 mdontu-l kernel: Modules linked in: hdaps(O) tp_smapi(O) thinkpad_ec(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) iwldvm iwlwifi e1000e
> Aug  6 21:37:37 mdontu-l kernel: CPU: 3 PID: 4823 Comm: X Tainted: G           O  3.16.0-gentoo #2
> Aug  6 21:37:37 mdontu-l kernel: Hardware name: LENOVO 4178A4G/4178A4G, BIOS 83ET76WW (1.46 ) 07/05/2013
> Aug  6 21:37:37 mdontu-l kernel:  0000000000000009 ffff88041d63fbf8 ffffffff93c212a4 0000000000000000
> Aug  6 21:37:37 mdontu-l kernel:  ffff88041d63fc30 ffffffff930e3a2d 0000000000000000 ffff880427b7c000
> Aug  6 21:37:37 mdontu-l kernel:  ffff880426f380a8 ffff880426ddf800 ffff880426ddf800 ffff88041d63fc40
> Aug  6 21:37:37 mdontu-l kernel: Call Trace:
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff93c212a4>] dump_stack+0x45/0x56
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff930e3a2d>] warn_slowpath_common+0x7d/0xa0
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff930e3b0a>] warn_slowpath_null+0x1a/0x20
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff936994dc>] intel_crtc_wait_for_pending_flips+0x16c/0x180
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff931240f0>] ? __wake_up_sync+0x20/0x20
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9369c753>] intel_crtc_disable_planes+0x33/0x1c0
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9369cd20>] ironlake_crtc_disable+0x50/0x970
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff936457bf>] ? drm_modeset_lock+0x2f/0xd0
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff93c27fe2>] ? mutex_lock+0x12/0x30
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9369e0af>] intel_crtc_update_dpms+0x6f/0xa0
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff936a1f09>] intel_connector_dpms+0x59/0x70
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9363c8c9>] drm_mode_obj_set_property_ioctl+0x399/0x3a0
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9363c900>] drm_mode_connector_property_set_ioctl+0x30/0x40
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9362b83f>] drm_ioctl+0x1df/0x680
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff935cf8dc>] ? backlight_generate_event+0x5c/0x80
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff935d0021>] ? brightness_store+0x91/0xd0
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff93244a0c>] ? fsnotify+0x27c/0x350
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9321b498>] do_vfs_ioctl+0x2c8/0x490
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9320b911>] ? __sb_end_write+0x31/0x60
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff93209512>] ? vfs_write+0x1c2/0x200
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff9321b6a1>] SyS_ioctl+0x41/0x80
> Aug  6 21:37:37 mdontu-l kernel:  [<ffffffff93c29b52>] system_call_fastpath+0x16/0x1b
> Aug  6 21:37:37 mdontu-l kernel: ---[ end trace 131b19886670715a ]---

If you can reproduce this somehow, please boot with drm.debug=0xe and
attach the complete dmesg up to the WARNING. We seem to loose track of
pageflips under obscure circumstances sometimes. We have more band-aids
queued up, but fixing the underlying issue would be better ofc.

Thanks, Daniel

> 
> X appeared to have stopped rendering (or nothing goes through), but the
> applications worked fine (I still had sound from a video). My video
> card is:
> 
> 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
>         Subsystem: Lenovo Device 21d0
>         Flags: bus master, fast devsel, latency 0, IRQ 43
>         Memory at f1400000 (64-bit, non-prefetchable) [size=4M]
>         Memory at e0000000 (64-bit, prefetchable) [size=256M]
>         I/O ports at 6000 [size=64]
>         Expansion ROM at <unassigned> [disabled]
>         Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
>         Capabilities: [d0] Power Management version 2
>         Capabilities: [a4] PCI Advanced Features
>         Kernel driver in use: i915
> 
> I was able to switch to the terminal and reboot.
> 
> I suspect this is new in 3.16 and I've noticed some other oddities
> since I upgraded from 3.15.8:
>  * when adjusting the screen brightness, the minimum setting is now
>    "LCD off";
>  * when watching a video in fullscreen, I can see a flicker every 10s
>    or so.
> 
> Thanks,
> 
> -- 
> Mihai Donțu
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch