drm/i915: get power domain in case the BIOS enabled eDP VDD
If I unplug the eDP monitor, the BIOS of my machine will enable the VDD bit, then when the driver loads it will think VDD is enabled. It will detect that the eDP is not enabled and return false from intel_edp_init_connector. This will trigger a call to edp_panel_vdd_off_sync(), which trigger a WARN saying that the refcount of the power domain is less than zero. The problem happens because the driver gets a refcount whenever it enables the VDD bit, and puts the refcount whenever it disables the VDD bit. But on this case, the BIOS enabled VDD, so all we do is to call put() without calling get() first, so the code added is there to make sure we always have the get() in case the BIOS enabled the bit. This regression was introduced in commit e9cb81a2 Author: Paulo Zanoni <paulo.r.zanoni@intel.com> Date: Thu Nov 21 13:47:23 2013 -0200 drm/i915: get a runtime PM reference when the panel VDD is on v2: - Rebase Tested-by: Chris Wilson <chris@chris-wilson.co.uk> (v1) Reviewed-by:Daniel Vetter <daniel.vetter@ffwll.ch> Cc: stable@vger.kernel.org (v3.13+) Signed-off-by:
Paulo Zanoni <paulo.r.zanoni@intel.com> Signed-off-by:
Jani Nikula <jani.nikula@intel.com>
parent
9953599b
Please register or sign in to comment