tree f570a619b4f6451be981975e05eb9b00a8c817fb
parent 50dd63a27bb0506a63137f38d72dead7dc1db584
author Ville Syrjälä <ville.syrjala@linux.intel.com> 1458052803 +0200
committer Ville Syrjälä <ville.syrjala@linux.intel.com> 1460484711 +0300

drm/i915: Power down the DSI PLL before reconfiguring it

On VLV at least, the BIOS may leave the DSI PLL enabled in some wonky
state where it just refuses to lock. Simply disabling the PLL before
reconfiguring it is not enough to fix it, but power gating the PLL
prior to reconfiguring does work.

This happens on BYT FFRD8 when booting with HDMI connected so the DSI
display will not be lit up by the BIOS.

Also we can remove the code for BXT that disables the PLL before
enabling it again.

v2: s/vlv/intel/ since BXT made thing generic
v3: Remove the BXT disable PLL before enable trick

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458052809-23426-11-git-send-email-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>