From 6b89cddee051945a83cc67436ad1680ba7d9f766 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 9 Jul 2014 22:35:53 +0200 Subject: [PATCH] Revert "drm/i915: Don't set the 8to6 dither flag when not scaling" 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 Cc: Pavel Machek Cc: Hans de Bruin Cc: stable@vger.kernel.org Acked-by: Pavel Machek Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_lvds.c | 7 +++++++ drivers/gpu/drm/i915/intel_panel.c | 8 ++++---- 2 files changed, 11 insertions(+), 4 deletions(-) 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; -- 2.7.4