Re: [PATCH] drm/i915: Apply the IBX transcoder A w/a for HDMI to SDVO as well

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Nov 21, 2012 at 10:44:23AM +0000, Chris Wilson wrote:
> As the SDVO/HDMI registers are multiplex, it is safe to assume that the
> w/a required for HDMI on IbexPoint, namely that the SDVO register cannot
> both be disabled and have selected transcoder B, is also required for
> SDVO. At least the modeset state checker detects that the transcoder
> selection is left in the undefined state, and so it appears sensible to
> apply the w/a:
> 
> [ 1814.480052] WARNING: at drivers/gpu/drm/i915/intel_display.c:1487 assert_pch_hdmi_disabled+0xad/0xb5()
> [ 1814.480053] Hardware name: Libretto W100
> [ 1814.480054] IBX PCH hdmi port still using transcoder B
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=57066
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Queued for -next, thanks for the patch.

> ---
>  drivers/gpu/drm/i915/intel_sdvo.c |   38 ++++++++++++++++++++++++++++++++++++-
>  1 file changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
> index 92baac2..b302ef4 100644
> --- a/drivers/gpu/drm/i915/intel_sdvo.c
> +++ b/drivers/gpu/drm/i915/intel_sdvo.c
> @@ -1228,6 +1228,30 @@ static void intel_disable_sdvo(struct intel_encoder *encoder)
>  
>  	temp = I915_READ(intel_sdvo->sdvo_reg);
>  	if ((temp & SDVO_ENABLE) != 0) {
> +		/* HW workaround for IBX, we need to move the port to
> +		 * transcoder A before disabling it. */
> +		if (HAS_PCH_IBX(encoder->base.dev)) {
> +			struct drm_crtc *crtc = encoder->base.crtc;
> +			int pipe = crtc ? to_intel_crtc(crtc)->pipe : -1;

All these "is the encoder enabled" and "do we have a crtc for sure" checks
remind me that we still have cruft all over the place, which should die
with the modeset rework. Work for 3.9 I guess ;-)
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch