[PATCH 25/72] gpu: ipu-v3: Consolidate mutex lock in ipu_dmfc_alloc_bandwidth()

[Steve Longerbeam]

The dmfc mutex was being acquired in ipu_dmfc_free_bandwidth(), freed,
then immediately re-acquired in ipu_dmfc_alloc_bandwidth(). Acquire
the lock once at the beginning of ipu_dmfc_alloc_bandwidth().

Signed-off-by: Steve Longerbeam <steve_longerbeam at mentor.com>
---
 drivers/gpu/ipu-v3/ipu-dmfc.c |   19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/ipu-v3/ipu-dmfc.c b/drivers/gpu/ipu-v3/ipu-dmfc.c
index 6ef4932..1823004 100644
--- a/drivers/gpu/ipu-v3/ipu-dmfc.c
+++ b/drivers/gpu/ipu-v3/ipu-dmfc.c
@@ -283,7 +283,7 @@ static int dmfc_find_slots(struct ipu_dmfc_priv *priv, int slots)
 	return -EBUSY;
 }
 
-void ipu_dmfc_free_bandwidth(struct dmfc_channel *dmfc)
+static void dmfc_free_bandwidth(struct dmfc_channel *dmfc)
 {
 	struct ipu_dmfc_priv *priv = dmfc->priv;
 	int i;
@@ -291,10 +291,8 @@ void ipu_dmfc_free_bandwidth(struct dmfc_channel *dmfc)
 	dev_dbg(priv->dev, "dmfc: freeing %d slots starting from segment %d\n",
 		dmfc->slots, dmfc->segment);
 
-	mutex_lock(&priv->mutex);
-
 	if (!dmfc->slots)
-		goto out;
+		return;
 
 	dmfc->slotmask = 0;
 	dmfc->slots = 0;
@@ -320,7 +318,14 @@ void ipu_dmfc_free_bandwidth(struct dmfc_channel *dmfc)
 					       priv->channels[i].segment,
 					       priv->channels[i].burstsize);
 	}
-out:
+}
+
+void ipu_dmfc_free_bandwidth(struct dmfc_channel *dmfc)
+{
+	struct ipu_dmfc_priv *priv = dmfc->priv;
+
+	mutex_lock(&priv->mutex);
+	dmfc_free_bandwidth(dmfc);
 	mutex_unlock(&priv->mutex);
 }
 EXPORT_SYMBOL_GPL(ipu_dmfc_free_bandwidth);
@@ -337,10 +342,10 @@ int ipu_dmfc_alloc_bandwidth(struct dmfc_channel *dmfc,
 		"dmfc: trying to allocate %ldMpixel/s for IPU channel %d\n",
 		bandwidth_pixel_per_second / 1000000, dmfc->data->ipu_channel);
 
-	ipu_dmfc_free_bandwidth(dmfc);
-
 	mutex_lock(&priv->mutex);
 
+	dmfc_free_bandwidth(dmfc);
+
 	if (slots > 8) {
 		ret = -EBUSY;
 		goto out;
-- 
1.7.9.5