[PATCH 1/2] drm/i915: do not ignore eDP bpc settings from vbt

[PATCH 1/2] drm/i915: do not ignore eDP bpc settings from vbt

[Jani Nikula]

There are laptops out there that need the eDP bpc from VBT. This is
effectively a revert of

commit 4344b813f105a19f793f1fd93ad775b784648b95
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Aug 10 11:10:20 2012 +0200

    drm/i915: ignore eDP bpc settings from vbt

but putting the VBT check after the EDID check to see them both in dmesg if
this clamps more than the EDID. We have enough history with bpc clamping to
warrant the extra debug info.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=47641
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=56401
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6d8a5ed..0997e60 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4151,6 +4151,17 @@ static bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc,
 			}
 		}
 
+		if (intel_encoder->type == INTEL_OUTPUT_EDP) {
+			/* Use VBT settings if we have an eDP panel */
+			unsigned int edp_bpc = dev_priv->edp.bpp / 3;
+
+			if (edp_bpc < display_bpc) {
+				DRM_DEBUG_KMS("clamping display bpc (was %d) to eDP (%d)\n", display_bpc, edp_bpc);
+				display_bpc = edp_bpc;
+			}
+			continue;
+		}
+
 		/*
 		 * HDMI is either 12 or 8, so if the display lets 10bpc sneak
 		 * through, clamp it down.  (Note: >12bpc will be caught below.)
-- 
1.7.9.5

[PATCH 2/2] drm/i915: do not default to 18 bpp for eDP if missing from VBT

[Jani Nikula]

Do not clamp eDP to 18 bpp by default if the eDP BDB is missing from VBT.

This is hopefully a better version of

commit 4344b813f105a19f793f1fd93ad775b784648b95
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Aug 10 11:10:20 2012 +0200

    drm/i915: ignore eDP bpc settings from vbt

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/intel_bios.c    |   11 ++---------
 drivers/gpu/drm/i915/intel_display.c |    2 +-
 2 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 0ed6baf..56846ed 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -499,12 +499,8 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 
 	edp = find_section(bdb, BDB_EDP);
 	if (!edp) {
-		if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp.support) {
-			DRM_DEBUG_KMS("No eDP BDB found but eDP panel "
-				      "supported, assume %dbpp panel color "
-				      "depth.\n",
-				      dev_priv->edp.bpp);
-		}
+		if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp.support)
+			DRM_DEBUG_KMS("No eDP BDB found but eDP panel supported.\n");
 		return;
 	}
 
@@ -657,9 +653,6 @@ init_vbt_defaults(struct drm_i915_private *dev_priv)
 	dev_priv->lvds_use_ssc = 1;
 	dev_priv->lvds_ssc_freq = intel_bios_ssc_frequency(dev, 1);
 	DRM_DEBUG_KMS("Set default to SSC at %dMHz\n", dev_priv->lvds_ssc_freq);
-
-	/* eDP data */
-	dev_priv->edp.bpp = 18;
 }
 
 static int __init intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0997e60..b11e8c1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4155,7 +4155,7 @@ static bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc,
 			/* Use VBT settings if we have an eDP panel */
 			unsigned int edp_bpc = dev_priv->edp.bpp / 3;
 
-			if (edp_bpc < display_bpc) {
+			if (edp_bpc && edp_bpc < display_bpc) {
 				DRM_DEBUG_KMS("clamping display bpc (was %d) to eDP (%d)\n", display_bpc, edp_bpc);
 				display_bpc = edp_bpc;
 			}
-- 
1.7.9.5

Re: [PATCH 2/2] drm/i915: do not default to 18 bpp for eDP if missing from VBT

[Daniel Vetter]

On Mon, Nov 12, 2012 at 02:33:45PM +0200, Jani Nikula wrote:
> Do not clamp eDP to 18 bpp by default if the eDP BDB is missing from VBT.
> 
> This is hopefully a better version of
> 
> commit 4344b813f105a19f793f1fd93ad775b784648b95
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Fri Aug 10 11:10:20 2012 +0200
> 
>     drm/i915: ignore eDP bpc settings from vbt
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Patch merged into -fixes, let's see what happens ;-)

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch