drm/i915: protect backlight registers and data with a spinlock
Backlight data and registers are fiddled through LVDS/eDP modeset
enable/disable hooks, backlight sysfs files, asle interrupts, and register
save/restore. Protect the backlight related registers and driver private
fields using a spinlock.
The locking in register save/restore covers a little more than is strictly
necessary, including non-modeset case, for simplicity.
v2: Cover register access, save/restore, i915_read_blc_pwm_ctl() and code
paths leading there.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 95a3cc3..f6f4839 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -960,6 +960,7 @@
struct {
int level;
bool enabled;
+ spinlock_t lock; /* bl registers and the above bl fields */
struct backlight_device *device;
} backlight;