drm/i915: Fix HW readout for crtc_clock in HDMI mode

The conversion during HDMI HW readout from port_clock to crtc_clock was
missed when HDMI 10bpc support was added, so fix that.

v2:
- Unscrew the non-HDMI case.

Fixes: cd9e11a8 ("drm/i915/icl: Add 10-bit support for hdmi")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109593
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190808162547.7009-1-imre.deak@intel.com
(cherry picked from commit 2969a78a)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -1465,8 +1465,8 @@ static void ddi_dotclock_get(struct intel_crtc_state *pipe_config)
 	else if (intel_crtc_has_dp_encoder(pipe_config))
 		dotclock = intel_dotclock_calculate(pipe_config->port_clock,
 						    &pipe_config->dp_m_n);
-	else if (pipe_config->has_hdmi_sink && pipe_config->pipe_bpp == 36)
-		dotclock = pipe_config->port_clock * 2 / 3;
+	else if (pipe_config->has_hdmi_sink && pipe_config->pipe_bpp > 24)
+		dotclock = pipe_config->port_clock * 24 / pipe_config->pipe_bpp;
 	else
 		dotclock = pipe_config->port_clock;
 

drivers/gpu/drm/i915/intel_drv.h

@@ -829,7 +829,7 @@ struct intel_crtc_state {
 
 	/*
 	 * Frequence the dpll for the port should run at. Differs from the
-	 * adjusted dotclock e.g. for DP or 12bpc hdmi mode. This is also
+	 * adjusted dotclock e.g. for DP or 10/12bpc hdmi mode. This is also
 	 * already multiplied by pixel_multiplier.
 	 */
 	int port_clock;