drm/i915/skl: Add warn about unsupported CDCLK rates
authorImre Deak <imre.deak@intel.com>
Fri, 8 Jun 2018 14:41:37 +0000 (17:41 +0300)
committerImre Deak <imre.deak@intel.com>
Mon, 11 Jun 2018 11:01:43 +0000 (14:01 +0300)
commit602a9de513d5a43ecaf7d0443eca41656165d3c4
tree672faaf0e0eaba4e37ac6ccfbe17b8323ed1e920
parent2b9a820318ebdf81f666be4daf7414d98123fefb
drm/i915/skl: Add warn about unsupported CDCLK rates

While checking workarounds related to the CDCLK PLL, I noticed that the
DMC firmware bits for WA#1183 are missing for SKL. After that I
clarified with HW people that it's not needed on SKL, since it doesn't
support eDP1.4 which would be the only thing requiring the problematic
CDCLK clock rates. So in theory we shouldn't ever choose these
frequencies, but add an assert in any case for catching such cases and
for documentation.

v2:
- Move the check to skl_set_cdclk and warn whenever using the
  corresponding VCO freq. (Ville)

v3:
- Actually check for the platform. (Ville)

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/20180608144137.7943-1-imre.deak@intel.com
drivers/gpu/drm/i915/intel_cdclk.c