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Imre Deak authored
On my APL the LSPCON firmware resumes in PCON mode as opposed to the expected LS mode. It also appears to be in a state where AUX DPCD reads will succeed but return garbage recovering only after a few hundreds of milliseconds. After the recovery time DPCD reads will result in the correct values and things will continue to work. If I2C over AUX is attempted during this recovery time (implying an AUX write transaction) the firmware won't recover and will stay in this broken state. As a workaround check if the firmware is in PCON state after resume and if so wait until the correct DPCD values are returned. For this we compare the branch descriptor with the one we cached during init time. If the firmware was in the LS state, we skip the w/a and continue as before. v2: - Use the DP descriptor value cached in intel_dp. (Jani) - Get to intel_dp using container_of(), instead of a cached ptr. (Shashank) - Use usleep_range() instead of msleep(). Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98353 Cc: Shashank Sharma <shashank.sharma@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Jani Nikula <jani.nikula@intel.com> Signed-off-by:
Imre Deak <imre.deak@intel.com> Reviewed-by:
Jani Nikula <jani.nikula@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1477326811-30431-9-git-send-email-imre.deak@intel.com
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