From 8ba2d18520ce380cf572e9902d9b3b91ece6c2c0 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 12 Apr 2013 15:18:37 +0300 Subject: 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 Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_suspend.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/gpu/drm/i915/i915_suspend.c') diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c index 41f0fdecfbdc..88b9a663944f 100644 --- a/drivers/gpu/drm/i915/i915_suspend.c +++ b/drivers/gpu/drm/i915/i915_suspend.c @@ -192,6 +192,7 @@ static void i915_restore_vga(struct drm_device *dev) static void i915_save_display(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; + unsigned long flags; /* Display arbitration control */ if (INTEL_INFO(dev)->gen <= 4) @@ -202,6 +203,8 @@ static void i915_save_display(struct drm_device *dev) if (!drm_core_check_feature(dev, DRIVER_MODESET)) i915_save_display_reg(dev); + spin_lock_irqsave(&dev_priv->backlight.lock, flags); + /* LVDS state */ if (HAS_PCH_SPLIT(dev)) { dev_priv->regfile.savePP_CONTROL = I915_READ(PCH_PP_CONTROL); @@ -222,6 +225,8 @@ static void i915_save_display(struct drm_device *dev) dev_priv->regfile.saveLVDS = I915_READ(LVDS); } + spin_unlock_irqrestore(&dev_priv->backlight.lock, flags); + if (!IS_I830(dev) && !IS_845G(dev) && !HAS_PCH_SPLIT(dev)) dev_priv->regfile.savePFIT_CONTROL = I915_READ(PFIT_CONTROL); @@ -257,6 +262,7 @@ static void i915_restore_display(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; u32 mask = 0xffffffff; + unsigned long flags; /* Display arbitration */ if (INTEL_INFO(dev)->gen <= 4) @@ -265,6 +271,8 @@ static void i915_restore_display(struct drm_device *dev) if (!drm_core_check_feature(dev, DRIVER_MODESET)) i915_restore_display_reg(dev); + spin_lock_irqsave(&dev_priv->backlight.lock, flags); + /* LVDS state */ if (INTEL_INFO(dev)->gen >= 4 && !HAS_PCH_SPLIT(dev)) I915_WRITE(BLC_PWM_CTL2, dev_priv->regfile.saveBLC_PWM_CTL2); @@ -304,6 +312,8 @@ static void i915_restore_display(struct drm_device *dev) I915_WRITE(PP_CONTROL, dev_priv->regfile.savePP_CONTROL); } + spin_unlock_irqrestore(&dev_priv->backlight.lock, flags); + /* only restore FBC info on the platform that supports FBC*/ intel_disable_fbc(dev); if (I915_HAS_FBC(dev)) { -- cgit v1.2.3