[Intel-gfx] [PATCH 08/25] drm/i915: detect PCH encoders on Haswell

[Daniel Vetter]

On Wed, May 09, 2012 at 03:37:15PM -0300, Eugeni Dodonov wrote:
> On Haswell, the recommended PCH-connected output is the one driven by DDI
> E in FDI mode, used for VGA connection. All the others are handled by the
> CPU.
> 
> Note that this does not accounts for Haswell/PPT combination yet, so if we
> encounter such combination an error message is thrown to indicate that
> things could go wrong.
> 
> Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c |   16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index f809d6a..96933cc 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2610,6 +2610,22 @@ static bool intel_crtc_driving_pch(struct drm_crtc *crtc)
>  		if (encoder->base.crtc != crtc)
>  			continue;
>  
> +		/* On Haswell, LPT PCH handles the VGA connection via FDI, and Haswell
> +		 * CPU handles all others */
> +		if (IS_HASWELL(dev)) {
> +			if (encoder->type == DRM_MODE_ENCODER_DAC) {
> +				/* It is still unclear how this would work on PPT, so throw up an error */
> +				if (!HAS_PCH_LPT(dev))
> +					DRM_ERROR("DAC detected on a non-LPT PCH, this probably won't work\n");

Hm, I guess we should move the LPT check out of the DAC check - after all
we could drive a DP output through FDI on a PPT. Or maybe not, which
implies that we have no clue in either case ;-)
-Daniel
> +
> +				return true;
> +			} else {
> +				DRM_DEBUG_KMS("Haswell detected encoder %d, assuming is CPU\n",
> +						encoder->type);
> +				return false;
> +			}
> +		}
> +
>  		switch (encoder->type) {
>  		case INTEL_OUTPUT_EDP:
>  			if (!intel_encoder_is_pch_edp(&encoder->base))
> -- 
> 1.7.10
> 
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-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48