gma500: frame buffer locking

If we are the console then a printk can hit us with a spin lock held (and
in fact the kernel will do its best to take the console printing lock).

In that case we cannot politely sleep when synching after an accelerated op
but must behave obnoxiously to be sure of getting the bits out.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 8 insertions, 6 deletions

diff --git a/drivers/gpu/drm/gma500/accel_2d.c b/drivers/gpu/drm/gma500/accel_2d.c
index f0cef7678d41..f0ce82aed654 100644
--- a/drivers/gpu/drm/gma500/accel_2d.c
+++ b/drivers/gpu/drm/gma500/accel_2d.c
@@ -111,8 +111,9 @@ static int psbfb_2d_submit(struct drm_psb_private *dev_priv, uint32_t *cmdbuf,
         int ret = 0;
         int i;
         unsigned submit_size;
+        unsigned long flags;
 
-        mutex_lock(&dev_priv->mutex_2d);
+        spin_lock_irqsave(&dev_priv->lock_2d, flags);
         while (size > 0) {
                 submit_size = (size < 0x60) ? size : 0x60;
                 size -= submit_size;
@@ -127,7 +128,7 @@ static int psbfb_2d_submit(struct drm_psb_private *dev_priv, uint32_t *cmdbuf,
 
                 (void)PSB_RSGX32(PSB_SGX_2D_SLAVE_PORT + i - 4);
         }
-        mutex_unlock(&dev_priv->mutex_2d);
+        spin_unlock_irqrestore(&dev_priv->lock_2d, flags);
         return ret;
 }
 
@@ -327,8 +328,9 @@ int psbfb_sync(struct fb_info *info)
         struct drm_psb_private *dev_priv = dev->dev_private;
         unsigned long _end = jiffies + DRM_HZ;
         int busy = 0;
+        unsigned long flags;
 
-        mutex_lock(&dev_priv->mutex_2d);
+        spin_lock_irqsave(&dev_priv->lock_2d, flags);
         /*
          * First idle the 2D engine.
          */
@@ -357,6 +359,6 @@ int psbfb_sync(struct fb_info *info)
                                         _PSB_C2B_STATUS_BUSY) != 0);
 
 out:
-        mutex_unlock(&dev_priv->mutex_2d);
+        spin_unlock_irqrestore(&dev_priv->lock_2d, flags);
         return (busy) ? -EBUSY : 0;
 }
diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index 862bb8182b76..add3156cd8bf 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -186,7 +186,7 @@ static int psb_do_init(struct drm_device *dev)
 
 
         spin_lock_init(&dev_priv->irqmask_lock);
-        mutex_init(&dev_priv->mutex_2d);
+        spin_lock_init(&dev_priv->lock_2d);
 
         PSB_WSGX32(0x00000000, PSB_CR_BIF_BANK0);
         PSB_WSGX32(0x00000000, PSB_CR_BIF_BANK1);
diff --git a/drivers/gpu/drm/gma500/psb_drv.h b/drivers/gpu/drm/gma500/psb_drv.h
index f46b3c1edb1d..5ec8edf65163 100644
--- a/drivers/gpu/drm/gma500/psb_drv.h
+++ b/drivers/gpu/drm/gma500/psb_drv.h
@@ -606,7 +606,7 @@ struct drm_psb_private {
         void *fbdev;
 
         /* 2D acceleration */
-        struct mutex mutex_2d;
+        spinlock_t lock_2d;
 };