From: Daniel Vetter Date: Wed, 30 Jan 2013 14:59:57 +0000 (+0100) Subject: drm/i915: kill cargo-culted locking from power well code X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6b25a88752e8e9dc33c700712059b094d3da3219;p=linux-beck.git drm/i915: kill cargo-culted locking from power well code We may not concurrently change the power wells code. Which is already guaranteed since modesets aren't concurrent. That leaves races against setup/teardown/suspend/resume, and for those we already (try) rather hard not to hit concurrent modesets. No debug WARN_ON added since that would require us to grab the modeset locks in init/suspend code. Which is again just cargo culting since just grabbing the locks in those paths isn't good enough, we need the right order of operations, too. Cc: Paulo Zanoni Reviewed-by: Rodrigo Vivi Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 64d65f564a7c..bec1f9ffba2d 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4088,8 +4088,6 @@ void intel_init_power_well(struct drm_device *dev) if (!IS_HASWELL(dev)) return; - mutex_lock(&dev->struct_mutex); - /* For now, we need the power well to be always enabled. */ intel_set_power_well(dev, true); @@ -4097,8 +4095,6 @@ void intel_init_power_well(struct drm_device *dev) * the driver is in charge now. */ if (I915_READ(HSW_PWR_WELL_BIOS) & HSW_PWR_WELL_ENABLE) I915_WRITE(HSW_PWR_WELL_BIOS, 0); - - mutex_unlock(&dev->struct_mutex); } /* Set up chip specific power management-related functions */