Re: [BUG/REGRESSION] DRM / i915 / 2.6.37 and 2.6.38-rc*: DVI output gets disabled/reenabled under load

From: Chris Wilson
Date: Tue Jan 25 2011 - 08:50:38 EST


On Tue, 25 Jan 2011 13:35:31 +0100, Knut Petersen <Knut_Petersen@xxxxxxxxxxx> wrote:
> Attached find the startup logs. Both debuglevel 0xf.

2.6.36:
> [ 2.699943] [drm:intel_sdvo_debug_write], SDVOC: W: 02 (SDVO_CMD_GET_DEVICE_CAPS)
> [ 2.736984] [drm:intel_sdvo_debug_response], SDVOC: R: 02 C2 01 01 01 3D 3E 00 (Success)

2.6.38:
> [ 2.561275] [drm:intel_sdvo_debug_write], SDVOC: W: 02 (SDVO_CMD_GET_DEVICE_CAPS)
> [ 2.565952] [drm:intel_sdvo_read_response], SDVOC: R: (Success) 02 C2 01 01 01 3D 3E 00
> [ 2.579730] [drm:intel_sdvo_get_capabilities], SDVO capabilities:
> [ 2.579735] vendor_id: 2
> [ 2.579736] device_id: 194
> [ 2.579737] device_rev_id: 1
> [ 2.579738] sdvo_version_major: 1
> [ 2.579739] sdvo_version_minor: 1
> [ 2.579740] sdvo_inputs_mask: 1
> [ 2.579741] smooth_scaling: 1
> [ 2.579742] sharp_scaling: 1
> [ 2.579743] up_scaling: 1
> [ 2.579744] down_scaling: 1
> [ 2.579745] stall_support: 0
> [ 2.579746] output_flags: 62

Both report output_flags of 0x3e, which includes VGA and a few
complementary TV out modes. The VGA-2 seems to be ignored by 2.6.36, but
does seem legitimate. Hmm.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre
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