gma500: power can be touched in IRQ state

So we need to use a spinlock here

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/gma500/power.c b/drivers/staging/gma500/power.c
index 79eb670..5cd5023 100644 (file)
--- a/drivers/staging/gma500/power.c
+++ b/drivers/staging/gma500/power.c
@@ -36,7 +36,7 @@
 #include <linux/pm_runtime.h>
 
 static struct mutex power_mutex;       /* Serialize power ops */
-static struct mutex power_ctrl_mutex;  /* Serialize power claim */
+static spinlock_t power_ctrl_lock;     /* Serialize power claim */
 
 /**
  *     gma_power_init          -       initialise power manager
@@ -55,8 +55,8 @@ void gma_power_init(struct drm_device *dev)
        dev_priv->display_power = true; /* We start active */
        dev_priv->display_count = 0;    /* Currently no users */
        dev_priv->suspended = false;    /* And not suspended */
+       spin_lock_init(&power_ctrl_lock);
        mutex_init(&power_mutex);
-       mutex_init(&power_ctrl_mutex);
 
        dev_priv->ops->init_pm(dev);
 }
@@ -247,13 +247,14 @@ bool gma_power_begin(struct drm_device *dev, bool force_on)
 {
        struct drm_psb_private *dev_priv = dev->dev_private;
        int ret;
+       unsigned long flags;
 
-       mutex_lock(&power_ctrl_mutex);
+       spin_lock_irqsave(&power_ctrl_lock, flags);
        /* Power already on ? */
        if (dev_priv->display_power) {
                dev_priv->display_count++;
                pm_runtime_get(&dev->pdev->dev);
-               mutex_unlock(&power_ctrl_mutex);
+               spin_unlock_irqrestore(&power_ctrl_lock, flags);
                return true;
        }
        if (force_on == false)
@@ -266,11 +267,11 @@ bool gma_power_begin(struct drm_device *dev, bool force_on)
                psb_irq_postinstall(dev);
                pm_runtime_get(&dev->pdev->dev);
                dev_priv->display_count++;
-               mutex_unlock(&power_ctrl_mutex);
+               spin_unlock_irqrestore(&power_ctrl_lock, flags);
                return true;
        }
 out_false:
-       mutex_unlock(&power_ctrl_mutex);
+       spin_unlock_irqrestore(&power_ctrl_lock, flags);
        return false;
 }
 
@@ -284,10 +285,11 @@ out_false:
 void gma_power_end(struct drm_device *dev)
 {
        struct drm_psb_private *dev_priv = dev->dev_private;
-       mutex_lock(&power_ctrl_mutex);
+       unsigned long flags;
+       spin_lock_irqsave(&power_ctrl_lock, flags);
        dev_priv->display_count--;
        WARN_ON(dev_priv->display_count < 0);
-       mutex_unlock(&power_ctrl_mutex);
+       spin_unlock_irqrestore(&power_ctrl_lock, flags);
        pm_runtime_put(&dev->pdev->dev);
 }