Commit d8b32247 authored by Daniel Vetter's avatar Daniel Vetter

drm/i915: use pipe_config for lvds dithering

Up to now we've relied on the bios to get this right for us. Let's try
out whether our code has improved a bit, since we should dither
always when the output bpp doesn't match the plane bpp.
- gen5+ should be fine, since we only use the bios hint as an upgrade.
- gen4 changes, since here dithering is still controlled in the lvds
  register.
- gen2/3 has implicit dithering depeding upon whether you use 2 or 3
  lvds pairs (which makes sense, since it only supports 8bpc pipe
  outpu configurations).
- hsw doesn't support lvds.

v2: Remove redudant dither setting.

v3: Completly drop reliance on dev_priv->lvds_dither.

v4: Enable dithering on gen2/3 only when we have a 18bpp panel, since
up-dithering to a 24bpp panel is not supported by the hw. Spotted by
Ville.

v5: Also only enable lvds port dithering on gen4 for 18bpp modes. In
practice this only excludes dithering a 10bpc plane down for a 24bpp
lvds panel. Not something we truly care about. Again noticed by Ville.

v6: Actually git add.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent c6bb3538
......@@ -5146,8 +5146,7 @@ static int ironlake_get_refclk(struct drm_crtc *crtc)
}
static void ironlake_set_pipeconf(struct drm_crtc *crtc,
struct drm_display_mode *adjusted_mode,
bool dither)
struct drm_display_mode *adjusted_mode)
{
struct drm_i915_private *dev_priv = crtc->dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
......@@ -5176,7 +5175,7 @@ static void ironlake_set_pipeconf(struct drm_crtc *crtc,
}
val &= ~(PIPECONF_DITHER_EN | PIPECONF_DITHER_TYPE_MASK);
if (dither)
if (intel_crtc->config.dither)
val |= (PIPECONF_DITHER_EN | PIPECONF_DITHER_TYPE_SP);
val &= ~PIPECONF_INTERLACE_MASK;
......@@ -5259,8 +5258,7 @@ static void intel_set_pipe_csc(struct drm_crtc *crtc)
}
static void haswell_set_pipeconf(struct drm_crtc *crtc,
struct drm_display_mode *adjusted_mode,
bool dither)
struct drm_display_mode *adjusted_mode)
{
struct drm_i915_private *dev_priv = crtc->dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
......@@ -5270,7 +5268,7 @@ static void haswell_set_pipeconf(struct drm_crtc *crtc,
val = I915_READ(PIPECONF(cpu_transcoder));
val &= ~(PIPECONF_DITHER_EN | PIPECONF_DITHER_TYPE_MASK);
if (dither)
if (intel_crtc->config.dither)
val |= (PIPECONF_DITHER_EN | PIPECONF_DITHER_TYPE_SP);
val &= ~PIPECONF_INTERLACE_MASK_HSW;
......@@ -5631,7 +5629,7 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
bool is_lvds = false;
struct intel_encoder *encoder;
int ret;
bool dither, fdi_config_ok;
bool fdi_config_ok;
for_each_encoder_on_crtc(dev, crtc, encoder) {
switch (encoder->type) {
......@@ -5666,11 +5664,6 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
/* Ensure that the cursor is valid for the new mode before changing... */
intel_crtc_update_cursor(crtc, true);
/* determine panel color depth */
dither = intel_crtc->config.dither;
if (is_lvds && dev_priv->lvds_dither)
dither = true;
DRM_DEBUG_KMS("Mode for pipe %c:\n", pipe_name(pipe));
drm_mode_debug_printmodeline(mode);
......@@ -5737,7 +5730,7 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
fdi_config_ok = ironlake_check_fdi_lanes(intel_crtc);
ironlake_set_pipeconf(crtc, adjusted_mode, dither);
ironlake_set_pipeconf(crtc, adjusted_mode);
/* Set up the display plane register */
I915_WRITE(DSPCNTR(plane), DISPPLANE_GAMMA_ENABLE);
......@@ -5814,7 +5807,6 @@ static int haswell_crtc_mode_set(struct drm_crtc *crtc,
bool is_cpu_edp = false;
struct intel_encoder *encoder;
int ret;
bool dither;
for_each_encoder_on_crtc(dev, crtc, encoder) {
switch (encoder->type) {
......@@ -5850,9 +5842,6 @@ static int haswell_crtc_mode_set(struct drm_crtc *crtc,
/* Ensure that the cursor is valid for the new mode before changing... */
intel_crtc_update_cursor(crtc, true);
/* determine panel color depth */
dither = intel_crtc->config.dither;
DRM_DEBUG_KMS("Mode for pipe %c:\n", pipe_name(pipe));
drm_mode_debug_printmodeline(mode);
......@@ -5866,7 +5855,7 @@ static int haswell_crtc_mode_set(struct drm_crtc *crtc,
if (intel_crtc->config.has_pch_encoder)
ironlake_fdi_set_m_n(crtc);
haswell_set_pipeconf(crtc, adjusted_mode, dither);
haswell_set_pipeconf(crtc, adjusted_mode);
intel_set_pipe_csc(crtc);
......
......@@ -213,6 +213,11 @@ struct intel_crtc_config {
/* DP has a bunch of special case unfortunately, so mark the pipe
* accordingly. */
bool has_dp_encoder;
/*
* Enable dithering, used when the selected pipe bpp doesn't match the
* plane bpp.
*/
bool dither;
/* Controls for the clock computation, to override various stages. */
......
......@@ -136,7 +136,10 @@ static void intel_pre_pll_enable_lvds(struct intel_encoder *encoder)
* special lvds dither control bit on pch-split platforms, dithering is
* only controlled through the PIPECONF reg. */
if (INTEL_INFO(dev)->gen == 4) {
if (dev_priv->lvds_dither)
/* Bspec wording suggests that LVDS port dithering only exists
* for 18bpp panels. */
if (intel_crtc->config.dither &&
intel_crtc->config.pipe_bpp == 18)
temp |= LVDS_ENABLE_DITHER;
else
temp &= ~LVDS_ENABLE_DITHER;
......@@ -335,7 +338,13 @@ static bool intel_lvds_compute_config(struct intel_encoder *intel_encoder,
DRM_DEBUG_KMS("forcing display bpp (was %d) to LVDS (%d)\n",
pipe_config->pipe_bpp, lvds_bpp);
pipe_config->pipe_bpp = lvds_bpp;
/* Make sure pre-965 set dither correctly for 18bpp panels. */
if (INTEL_INFO(dev)->gen < 4 && lvds_bpp == 18)
pfit_control |= PANEL_8TO6_DITHER_ENABLE;
}
/*
* We have timings from the BIOS for the panel, put them in
* to the adjusted mode. The CRTC will be set up for this mode,
......@@ -470,10 +479,6 @@ static bool intel_lvds_compute_config(struct intel_encoder *intel_encoder,
pfit_pgm_ratios = 0;
}
/* Make sure pre-965 set dither correctly */
if (INTEL_INFO(dev)->gen < 4 && dev_priv->lvds_dither)
pfit_control |= PANEL_8TO6_DITHER_ENABLE;
if (pfit_control != lvds_encoder->pfit_control ||
pfit_pgm_ratios != lvds_encoder->pfit_pgm_ratios) {
lvds_encoder->pfit_control = pfit_control;
......
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