diff mbox

[1075/1094] Revert "drm/i915: Don't set the 8to6 dither flag when not scaling"

Message ID 1413889294-31328-1076-git-send-email-dheerajx.s.jamwal@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dheeraj Jamwal Oct. 21, 2014, 11:01 a.m. UTC 
From: Daniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit 773875bfb6737982903c42d1ee88cf60af80089c.

It is very much needed and the lack of dithering has been reported by
a large list of people with various gen2/3 hardware.

Also, the original patch was complete non-sense since the WARNING
backtraces in the references bugzilla are about
gmch_pfit.lvds_border_bits mismatch, not at all about the dither bit.
That one seems to work.

Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Hans de Bruin <jmdebruin@xmsnet.nl>
Cc: stable@vger.kernel.org
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 6b89cddee051945a83cc67436ad1680ba7d9f766)

Signed-off-by: Dheeraj Jamwal <dheerajx.s.jamwal@intel.com>
---
 drivers/gpu/drm/i915/intel_lvds.c  |    7 +++++++
 drivers/gpu/drm/i915/intel_panel.c |    8 ++++----
 2 files changed, 11 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 2312602..5e5a72f 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -111,6 +111,13 @@  static void intel_lvds_get_config(struct intel_encoder *encoder,
 
 	pipe_config->adjusted_mode.flags |= flags;
 
+	/* gen2/3 store dither state in pfit control, needs to match */
+	if (INTEL_INFO(dev)->gen < 4) {
+		tmp = I915_READ(PFIT_CONTROL);
+
+		pipe_config->gmch_pfit.control |= tmp & PANEL_8TO6_DITHER_ENABLE;
+	}
+
 	dotclock = pipe_config->port_clock;
 
 	if (HAS_PCH_SPLIT(dev_priv->dev))
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 628cd89..12b02fe 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -361,16 +361,16 @@  void intel_gmch_panel_fitting(struct intel_crtc *intel_crtc,
 		pfit_control |= ((intel_crtc->pipe << PFIT_PIPE_SHIFT) |
 				 PFIT_FILTER_FUZZY);
 
-	/* Make sure pre-965 set dither correctly for 18bpp panels. */
-	if (INTEL_INFO(dev)->gen < 4 && pipe_config->pipe_bpp == 18)
-		pfit_control |= PANEL_8TO6_DITHER_ENABLE;
-
 out:
 	if ((pfit_control & PFIT_ENABLE) == 0) {
 		pfit_control = 0;
 		pfit_pgm_ratios = 0;
 	}
 
+	/* Make sure pre-965 set dither correctly for 18bpp panels. */
+	if (INTEL_INFO(dev)->gen < 4 && pipe_config->pipe_bpp == 18)
+		pfit_control |= PANEL_8TO6_DITHER_ENABLE;
+
 	pipe_config->gmch_pfit.control = pfit_control;
 	pipe_config->gmch_pfit.pgm_ratios = pfit_pgm_ratios;
 	pipe_config->gmch_pfit.lvds_border_bits = border;