diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2018-01-22 19:41:31 +0200 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2018-01-24 20:09:29 +0200 |
| commit | 0519c102f5285476d7868a387bdb6c58385e4074 (patch) | |
| tree | 3e5adb8d546c50537447b3b76ce329200127018a /drivers/gpu/drm/i915/intel_ddi.c | |
| parent | c19e1124e7e8cb1f8fbb685fd9b7d0a42087bd62 (diff) | |
drm/i915: Implement display w/a #1143
Apparently SKL/KBL/CFL need some manual help to get the
programmed HDMI vswing to stick. Implement the relevant
workaround (display w/a #1143).
Note that the relevant chicken bits live in a transcoder register
even though the bits affect a specific DDI port rather than a
specific transcoder. Hence we must pick the correct transcoder
register instance based on the port rather than based on the
cpu_transcoder.
Also note that for completeness I included support for DDI A/E
in the code even though we never have HDMI on those ports.
v2: CFL needs the w/a as well (Rodrigo and Art)
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Art Runyan <arthur.j.runyan@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180122174131.28046-1-ville.syrjala@linux.intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_ddi.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ddi.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index f51645a08dca..2756a69b6207 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -2404,6 +2404,48 @@ static void intel_enable_ddi_hdmi(struct intel_encoder *encoder, crtc_state->hdmi_high_tmds_clock_ratio, crtc_state->hdmi_scrambling); + /* Display WA #1143: skl,kbl,cfl */ + if (IS_GEN9_BC(dev_priv)) { + /* + * For some reason these chicken bits have been + * stuffed into a transcoder register, event though + * the bits affect a specific DDI port rather than + * a specific transcoder. + */ + static const enum transcoder port_to_transcoder[] = { + [PORT_A] = TRANSCODER_EDP, + [PORT_B] = TRANSCODER_A, + [PORT_C] = TRANSCODER_B, + [PORT_D] = TRANSCODER_C, + [PORT_E] = TRANSCODER_A, + }; + enum transcoder transcoder = port_to_transcoder[port]; + u32 val; + + val = I915_READ(CHICKEN_TRANS(transcoder)); + + if (port == PORT_E) + val |= DDIE_TRAINING_OVERRIDE_ENABLE | + DDIE_TRAINING_OVERRIDE_VALUE; + else + val |= DDI_TRAINING_OVERRIDE_ENABLE | + DDI_TRAINING_OVERRIDE_VALUE; + + I915_WRITE(CHICKEN_TRANS(transcoder), val); + POSTING_READ(CHICKEN_TRANS(transcoder)); + + udelay(1); + + if (port == PORT_E) + val &= ~(DDIE_TRAINING_OVERRIDE_ENABLE | + DDIE_TRAINING_OVERRIDE_VALUE); + else + val &= ~(DDI_TRAINING_OVERRIDE_ENABLE | + DDI_TRAINING_OVERRIDE_VALUE); + + I915_WRITE(CHICKEN_TRANS(transcoder), val); + } + /* In HDMI/DVI mode, the port width, and swing/emphasis values * are ignored so nothing special needs to be done besides * enabling the port. |