diff mbox series

[2/3] drm/i915: Update eDP fast link training link rate parsing

Message ID 20220601151907.18725-3-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915: Parse more eDP link rate stuff from VBT | expand

Commit Message

Ville Syrjälä June 1, 2022, 3:19 p.m. UTC 
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

We're not parsing the 5.4 Gbps value for the old eDP fast link
training link rate, nor are we parsing the new fast link training
link rate field. Remedy both.

Note that we're not even using this information for anything
currently, so should perhaps just nuke it all unless someone
is planning on implementing fast link training finally...

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_bios.c     | 32 ++++++++++++-------
 drivers/gpu/drm/i915/display/intel_vbt_defs.h |  1 +
 2 files changed, 21 insertions(+), 12 deletions(-)

Comments

Jani Nikula June 2, 2022, 9:38 a.m. UTC | #1 
On Wed, 01 Jun 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> We're not parsing the 5.4 Gbps value for the old eDP fast link
> training link rate, nor are we parsing the new fast link training
> link rate field. Remedy both.
>
> Note that we're not even using this information for anything
> currently, so should perhaps just nuke it all unless someone
> is planning on implementing fast link training finally...
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_bios.c     | 32 ++++++++++++-------
>  drivers/gpu/drm/i915/display/intel_vbt_defs.h |  1 +
>  2 files changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index c42b9e7d0dce..d701854dc429 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -1367,18 +1367,26 @@ parse_edp(struct drm_i915_private *i915,
>  
>  	panel->vbt.edp.pps = *edp_pps;
>  
> -	switch (edp_link_params->rate) {
> -	case EDP_RATE_1_62:
> -		panel->vbt.edp.rate = DP_LINK_BW_1_62;
> -		break;
> -	case EDP_RATE_2_7:
> -		panel->vbt.edp.rate = DP_LINK_BW_2_7;
> -		break;
> -	default:
> -		drm_dbg_kms(&i915->drm,
> -			    "VBT has unknown eDP link rate value %u\n",
> -			     edp_link_params->rate);
> -		break;
> +	if (i915->vbt.version >= 224) {
> +		panel->vbt.edp.rate =
> +			edp->edp_fast_link_training_rate[panel_type] * 2;

So this is in units of 200 kHz.

> +	} else {
> +		switch (edp_link_params->rate) {
> +		case EDP_RATE_1_62:
> +			panel->vbt.edp.rate = DP_LINK_BW_1_62;

However the DP_LINK_BW_* stuff are the values to be written to DPCD. So
different things end up in panel->vbt.edp.rate depending on VBT
version. It's a mess. Should probably have the rate there and throw out
the DP_LINK_BW_* macros.

Otherwise, the logic seems fine.

BR,
Jani.

> +			break;
> +		case EDP_RATE_2_7:
> +			panel->vbt.edp.rate = DP_LINK_BW_2_7;
> +			break;
> +		case EDP_RATE_5_4:
> +			panel->vbt.edp.rate = DP_LINK_BW_5_4;
> +			break;
> +		default:
> +			drm_dbg_kms(&i915->drm,
> +				    "VBT has unknown eDP link rate value %u\n",
> +				    edp_link_params->rate);
> +			break;
> +		}
>  	}
>  
>  	switch (edp_link_params->lanes) {
> diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> index 14f1e1cc92c5..58aee0a040cf 100644
> --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> @@ -638,6 +638,7 @@ struct bdb_sdvo_panel_dtds {
>  #define EDP_30BPP	2
>  #define EDP_RATE_1_62	0
>  #define EDP_RATE_2_7	1
> +#define EDP_RATE_5_4	2
>  #define EDP_LANE_1	0
>  #define EDP_LANE_2	1
>  #define EDP_LANE_4	3
Ville Syrjälä June 2, 2022, 5:57 p.m. UTC | #2 
On Thu, Jun 02, 2022 at 12:38:48PM +0300, Jani Nikula wrote:
> On Wed, 01 Jun 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > We're not parsing the 5.4 Gbps value for the old eDP fast link
> > training link rate, nor are we parsing the new fast link training
> > link rate field. Remedy both.
> >
> > Note that we're not even using this information for anything
> > currently, so should perhaps just nuke it all unless someone
> > is planning on implementing fast link training finally...
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_bios.c     | 32 ++++++++++++-------
> >  drivers/gpu/drm/i915/display/intel_vbt_defs.h |  1 +
> >  2 files changed, 21 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> > index c42b9e7d0dce..d701854dc429 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> > @@ -1367,18 +1367,26 @@ parse_edp(struct drm_i915_private *i915,
> >  
> >  	panel->vbt.edp.pps = *edp_pps;
> >  
> > -	switch (edp_link_params->rate) {
> > -	case EDP_RATE_1_62:
> > -		panel->vbt.edp.rate = DP_LINK_BW_1_62;
> > -		break;
> > -	case EDP_RATE_2_7:
> > -		panel->vbt.edp.rate = DP_LINK_BW_2_7;
> > -		break;
> > -	default:
> > -		drm_dbg_kms(&i915->drm,
> > -			    "VBT has unknown eDP link rate value %u\n",
> > -			     edp_link_params->rate);
> > -		break;
> > +	if (i915->vbt.version >= 224) {
> > +		panel->vbt.edp.rate =
> > +			edp->edp_fast_link_training_rate[panel_type] * 2;
> 
> So this is in units of 200 kHz.

Right. Or even more specifically it's 200 kbps units (based on the example
values in the spec). So we'll want *20 here to get the 10 kbps units we
use.

> 
> > +	} else {
> > +		switch (edp_link_params->rate) {
> > +		case EDP_RATE_1_62:
> > +			panel->vbt.edp.rate = DP_LINK_BW_1_62;
> 
> However the DP_LINK_BW_* stuff are the values to be written to DPCD. So
> different things end up in panel->vbt.edp.rate depending on VBT
> version. It's a mess. Should probably have the rate there and throw out
> the DP_LINK_BW_* macros.

Oh right, I forgot those are the DPCD values. I'll switch to real
numbers here.

> 
> Otherwise, the logic seems fine.
> 
> BR,
> Jani.
> 
> > +			break;
> > +		case EDP_RATE_2_7:
> > +			panel->vbt.edp.rate = DP_LINK_BW_2_7;
> > +			break;
> > +		case EDP_RATE_5_4:
> > +			panel->vbt.edp.rate = DP_LINK_BW_5_4;
> > +			break;
> > +		default:
> > +			drm_dbg_kms(&i915->drm,
> > +				    "VBT has unknown eDP link rate value %u\n",
> > +				    edp_link_params->rate);
> > +			break;
> > +		}
> >  	}
> >  
> >  	switch (edp_link_params->lanes) {
> > diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> > index 14f1e1cc92c5..58aee0a040cf 100644
> > --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> > +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> > @@ -638,6 +638,7 @@ struct bdb_sdvo_panel_dtds {
> >  #define EDP_30BPP	2
> >  #define EDP_RATE_1_62	0
> >  #define EDP_RATE_2_7	1
> > +#define EDP_RATE_5_4	2
> >  #define EDP_LANE_1	0
> >  #define EDP_LANE_2	1
> >  #define EDP_LANE_4	3
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index c42b9e7d0dce..d701854dc429 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -1367,18 +1367,26 @@  parse_edp(struct drm_i915_private *i915,
 
 	panel->vbt.edp.pps = *edp_pps;
 
-	switch (edp_link_params->rate) {
-	case EDP_RATE_1_62:
-		panel->vbt.edp.rate = DP_LINK_BW_1_62;
-		break;
-	case EDP_RATE_2_7:
-		panel->vbt.edp.rate = DP_LINK_BW_2_7;
-		break;
-	default:
-		drm_dbg_kms(&i915->drm,
-			    "VBT has unknown eDP link rate value %u\n",
-			     edp_link_params->rate);
-		break;
+	if (i915->vbt.version >= 224) {
+		panel->vbt.edp.rate =
+			edp->edp_fast_link_training_rate[panel_type] * 2;
+	} else {
+		switch (edp_link_params->rate) {
+		case EDP_RATE_1_62:
+			panel->vbt.edp.rate = DP_LINK_BW_1_62;
+			break;
+		case EDP_RATE_2_7:
+			panel->vbt.edp.rate = DP_LINK_BW_2_7;
+			break;
+		case EDP_RATE_5_4:
+			panel->vbt.edp.rate = DP_LINK_BW_5_4;
+			break;
+		default:
+			drm_dbg_kms(&i915->drm,
+				    "VBT has unknown eDP link rate value %u\n",
+				    edp_link_params->rate);
+			break;
+		}
 	}
 
 	switch (edp_link_params->lanes) {
diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
index 14f1e1cc92c5..58aee0a040cf 100644
--- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
+++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
@@ -638,6 +638,7 @@  struct bdb_sdvo_panel_dtds {
 #define EDP_30BPP	2
 #define EDP_RATE_1_62	0
 #define EDP_RATE_2_7	1
+#define EDP_RATE_5_4	2
 #define EDP_LANE_1	0
 #define EDP_LANE_2	1
 #define EDP_LANE_4	3