[Intel-gfx] [PATCH] drm/i915/edp: Use fixed panel timing information from VBT

[Zhenyu Wang]

On 2010.05.12 11:29:53 -0400, Adam Jackson wrote:
> eDP panels are often fixed-rate.  Grab the link speed and lane count
> from the VBT and use those instead of trying to compute them.
> 
> Signed-off-by: Adam Jackson <ajax at redhat.com>
> ---

Looks good to me, and it might just fix
https://bugs.freedesktop.org/show_bug.cgi?id=28070

We just have one 1366x768 panel which works fine for me last time I tried,
but that bug has a larger one, and from log it seems driver still use 1.6Ghz
which may lead to the problem as you addressed. I'll ask the reporter to
try your patch.

Thanks!

>  drivers/gpu/drm/i915/i915_drv.h   |    2 ++
>  drivers/gpu/drm/i915/intel_bios.c |   18 ++++++++++++++++++
>  drivers/gpu/drm/i915/intel_dp.c   |   29 +++++++++++++++++++++++++++++
>  3 files changed, 49 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 7f797ef..78212c2 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -326,6 +326,8 @@ typedef struct drm_i915_private {
>  	unsigned int edp_support:1;
>  	int lvds_ssc_freq;
>  	int edp_bpp;
> +	int edp_link_bw;
> +	int edp_lane_count;
>  
>  	struct notifier_block lid_notifier;
>  
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 4c748d8..ac60a6f 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -26,6 +26,7 @@
>   */
>  #include "drmP.h"
>  #include "drm.h"
> +#include "drm_dp_helper.h"
>  #include "i915_drm.h"
>  #include "i915_drv.h"
>  #include "intel_bios.h"
> @@ -437,6 +438,23 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>  		dev_priv->edp_bpp = 30;
>  		break;
>  	}
> +
> +	if (edp->link_params[panel_type].rate == EDP_RATE_1_62)
> +	    dev_priv->edp_link_bw = DP_LINK_BW_1_62;
> +	else
> +	    dev_priv->edp_link_bw = DP_LINK_BW_2_7;
> +
> +	switch (edp->link_params[panel_type].lanes) {
> +	case EDP_LANE_1:
> +	    dev_priv->edp_lane_count = 1;
> +	    break;
> +	case EDP_LANE_2:
> +	    dev_priv->edp_lane_count = 2;
> +	    break;
> +	case EDP_LANE_4:
> +	    dev_priv->edp_lane_count = 4;
> +	    break;
> +	}
>  }
>  
>  static void
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index f6299bb..c77c567 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -494,6 +494,31 @@ intel_dp_i2c_init(struct intel_encoder *intel_encoder,
>  }
>  
>  static bool
> +intel_edp_mode_fixup(struct drm_encoder *encoder, struct drm_display_mode *mode,
> +		     struct drm_display_mode *adjusted_mode)
> +{
> +	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
> +	struct intel_encoder *intel_encoder = enc_to_intel_encoder(encoder);
> +	struct intel_dp_priv *dp_priv = intel_encoder->dev_priv;
> +
> +	/* the VBT tells us what the panel demands. hopefully it exists. */
> +	if (dev_priv->edp_lane_count == 0) {
> +		DRM_DEBUG_KMS("no eDP block found, guessing parameters\n");
> +		return false;
> +	}
> +
> +	dp_priv->link_bw = dev_priv->edp_link_bw;
> +	dp_priv->lane_count = dev_priv->edp_lane_count;
> +	adjusted_mode->clock = intel_dp_link_clock(dp_priv->link_bw);
> +
> +	DRM_DEBUG_KMS("eDP link bw %02x lane count %d clock %d\n",
> +		      dp_priv->link_bw, dp_priv->lane_count,
> +		      adjusted_mode->clock);
> +
> +	return true;
> +}
> +
> +static bool
>  intel_dp_mode_fixup(struct drm_encoder *encoder, struct drm_display_mode *mode,
>  		    struct drm_display_mode *adjusted_mode)
>  {
> @@ -504,6 +529,10 @@ intel_dp_mode_fixup(struct drm_encoder *encoder, struct drm_display_mode *mode,
>  	int max_clock = intel_dp_max_link_bw(intel_encoder) == DP_LINK_BW_2_7 ? 1 : 0;
>  	static int bws[2] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7 };
>  
> +	if (IS_eDP(intel_encoder))
> +	    if (intel_edp_mode_fixup(encoder, mode, adjusted_mode))
> +		return true;
> +
>  	for (lane_count = 1; lane_count <= max_lane_count; lane_count <<= 1) {
>  		for (clock = 0; clock <= max_clock; clock++) {
>  			int link_avail = intel_dp_link_clock(bws[clock]) * lane_count;
> -- 
> 1.7.0.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Open Source Technology Center, Intel ltd.

$gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://lists.freedesktop.org/archives/intel-gfx/attachments/20100513/651e09c9/attachment.sig>