[Intel-gfx] [PATCH] drm/i915: Don't call encoder's get_config unless encoder is active

[Daniel Vetter]

On Mon, Aug 05, 2013 at 05:57:48PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> The SDVO code tries to compare the encoder's and crtc's idea of the
> pixel_multiplier. Normally they have to match, but when transitioning
> to DPMS off, we turn off the pipe before reading out the pipe_config,
> so the pixel_multiplier in the pipe_config will be 0, whereas the
> encoder will still have its pixel_multiplier set to whatever value we
> were using when the display was active. This leads to a warning
> from intel_modeset_check_state().
> 
> WARNING: CPU: 1 PID: 2846 at drivers/gpu/drm/i915/intel_sdvo.c:1378 intel_sdvo_get_config+0x158/0x160()
> SDVO pixel multiplier mismatch, port: 0, encoder: 1
> Modules linked in: snd_hda_codec_idt snd_hda_intel snd_hda_codec snd_hwdep
> CPU: 1 PID: 2846 Comm: Xorg Not tainted 3.11.0-rc3-00208-gbe1e8d7-dirty #19
> Hardware name: Apple Computer, Inc. Macmini1,1/Mac-F4208EC8, BIOS  MM11.88Z.0055.B03.0604071521 04/07/06
>  00000000 00000000 ef0afa54 c1597bbb c1737ea4 ef0afa84 c10392ca c1737e6c
>  ef0afab0 00000b1e c1737ea4 00000562 c12dfbe8 c12dfbe8 ef0afb14 00000000
>  f697ec00 ef0afa9c c103936e 00000009 ef0afa94 c1737e6c ef0afab0 ef0afadc
> Call Trace:
>  [<c1597bbb>] dump_stack+0x41/0x56
>  [<c10392ca>] warn_slowpath_common+0x7a/0xa0
>  [<c103936e>] warn_slowpath_fmt+0x2e/0x30
>  [<c12dfbe8>] intel_sdvo_get_config+0x158/0x160
>  [<c12c3220>] check_crtc_state+0x1e0/0xb10
>  [<c12cdc7d>] intel_modeset_check_state+0x29d/0x7c0
>  [<c12dfe5c>] intel_sdvo_dpms+0x5c/0xa0
>  [<c12985de>] drm_mode_obj_set_property_ioctl+0x40e/0x420
>  [<c1298625>] drm_mode_connector_property_set_ioctl+0x35/0x40
>  [<c1289294>] drm_ioctl+0x3e4/0x540
>  [<c10fc1a2>] do_vfs_ioctl+0x72/0x570
>  [<c10fc72f>] SyS_ioctl+0x8f/0xa0
>  [<c159b7fa>] sysenter_do_call+0x12/0x22
> ---[ end trace 7ce940aff1366d60 ]---
> 
> Fix the problem by skipping the encoder get_config() function for
> inactive encoders.
> 
> Tested-by: Linus Torvalds <torvalds at linux-foundation.org>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Picked up for -fixes, thanks for the patch.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch