drm/i915: Fix pipe_bpp readout for BXT/GLK DSI

The only bpc information in pipe registers for BXT/GLK DSI
is the PIPEMISC dither bpc. Let's try to use that to read
out pipe_bpp on these platforms. However, I'm not sure if
this will be correctly populated by the GOP since bspec
suggests it's only needed if dithering is actually enabled.
If not I guess we'll have to go one step further and
extract pipe_bpp from the DSI pixel format when dithering
is disabled.

Cc: Hans de Goede <hdegoede@redhat.com>
Fixes: ca0b04db14 ("drm/i915/dsi: Fix pipe_bpp for handling for 6 bpc pixel-formats")
References: https://bugs.freedesktop.org/show_bug.cgi?id=109516
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190405141349.11950-1-ville.syrjala@linux.intel.com
(cherry picked from commit 499653501b)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Ville Syrjälä 2019-04-05 17:13:49 +03:00 committed by Rodrigo Vivi
parent 57cbec02f9
commit e1b7058ece
1 changed files with 24 additions and 0 deletions

View File

@ -256,6 +256,28 @@ static void band_gap_reset(struct drm_i915_private *dev_priv)
mutex_unlock(&dev_priv->sb_lock);
}
static int bdw_get_pipemisc_bpp(struct intel_crtc *crtc)
{
struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
u32 tmp;
tmp = I915_READ(PIPEMISC(crtc->pipe));
switch (tmp & PIPEMISC_DITHER_BPC_MASK) {
case PIPEMISC_DITHER_6_BPC:
return 18;
case PIPEMISC_DITHER_8_BPC:
return 24;
case PIPEMISC_DITHER_10_BPC:
return 30;
case PIPEMISC_DITHER_12_BPC:
return 36;
default:
MISSING_CASE(tmp);
return 0;
}
}
static int intel_dsi_compute_config(struct intel_encoder *encoder,
struct intel_crtc_state *pipe_config,
struct drm_connector_state *conn_state)
@ -1071,6 +1093,8 @@ static void bxt_dsi_get_pipe_config(struct intel_encoder *encoder,
bpp = mipi_dsi_pixel_format_to_bpp(
pixel_format_from_register_bits(fmt));
pipe_config->pipe_bpp = bdw_get_pipemisc_bpp(crtc);
/* Enable Frame time stamo based scanline reporting */
adjusted_mode->private_flags |=
I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;