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

This reverts commit 773875bfb6.

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>
This commit is contained in:
Daniel Vetter 2014-07-09 22:35:53 +02:00
parent 1795cd9b3a
commit 6b89cddee0
2 changed files with 11 additions and 4 deletions

View File

@ -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))

View File

@ -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;