From 41b1b29eda52b125f7ad2b8a2090987e89206fdd Mon Sep 17 00:00:00 2001
From: Sakshi Agrawal <sakshia@codeaurora.org>
Date: Tue, 19 Mar 2013 12:45:04 -0600
Subject: [PATCH] msm: kgsl: Use ERR_PTR to return errors from
 kgsl_create_context()

Normally kgsl_create_context() returns a pointer to a new context.
In case of errors it just returns NULL pointer, and that doesn't allow
to propagate the right error code back to the user via
kgsl_ioctl_drawctxt_create()
This fix modifies kgsl_create_context to use ERR_PTR macro for passing
error codes to its caller.

Change-Id: I447c1765828912b0994bcae67a73864e62eef9b6
Signed-off-by: Vladimir Razgulin <vrazguli@codeaurora.org>
Signed-off-by: Sakshi Agrawal <sakshia@codeaurora.org>
---
 drivers/gpu/msm/kgsl.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/msm/kgsl.c b/drivers/gpu/msm/kgsl.c
index e0666dd9ab4..2ce8ab46513 100644
--- a/drivers/gpu/msm/kgsl.c
+++ b/drivers/gpu/msm/kgsl.c
@@ -254,14 +254,19 @@ kgsl_create_context(struct kgsl_device_private *dev_priv)
 
 	context = kzalloc(sizeof(*context), GFP_KERNEL);
 
-	if (context == NULL)
-		return NULL;
+	if (context == NULL) {
+		KGSL_DRV_INFO(dev_priv->device, "kzalloc(%d) failed\n",
+				sizeof(*context));
+		return ERR_PTR(-ENOMEM);
+	}
 
 	while (1) {
 		if (idr_pre_get(&dev_priv->device->context_idr,
 				GFP_KERNEL) == 0) {
-			kfree(context);
-			return NULL;
+			KGSL_DRV_INFO(dev_priv->device,
+					"idr_pre_get: ENOMEM\n");
+			ret = -ENOMEM;
+			goto func_end;
 		}
 
 		ret = idr_get_new_above(&dev_priv->device->context_idr,
@@ -271,10 +276,8 @@ kgsl_create_context(struct kgsl_device_private *dev_priv)
 			break;
 	}
 
-	if (ret) {
-		kfree(context);
-		return NULL;
-	}
+	if (ret)
+		goto func_end;
 
 	/* MAX - 1, there is one memdesc in memstore for device info */
 	if (id >= KGSL_MEMSTORE_MAX) {
@@ -282,15 +285,16 @@ kgsl_create_context(struct kgsl_device_private *dev_priv)
 				"ctxts due to memstore limitation\n",
 				KGSL_MEMSTORE_MAX);
 		idr_remove(&dev_priv->device->context_idr, id);
-		kfree(context);
-		return NULL;
+		ret = -ENOSPC;
+		goto func_end;
 	}
 
 	kref_init(&context->refcount);
 	context->id = id;
 	context->dev_priv = dev_priv;
 
-	if (kgsl_sync_timeline_create(context)) {
+	ret = kgsl_sync_timeline_create(context);
+	if (ret) {
 		idr_remove(&dev_priv->device->context_idr, id);
 		goto func_end;
 	}
@@ -312,7 +316,7 @@ kgsl_create_context(struct kgsl_device_private *dev_priv)
 func_end:
 	if (ret) {
 		kfree(context);
-		return NULL;
+		return ERR_PTR(ret);
 	}
 
 	return context;
@@ -1280,8 +1284,8 @@ static long kgsl_ioctl_drawctxt_create(struct kgsl_device_private *dev_priv,
 
 	context = kgsl_create_context(dev_priv);
 
-	if (context == NULL) {
-		result = -ENOMEM;
+	if (IS_ERR(context)) {
+		result = PTR_ERR(context);
 		goto done;
 	}
 
@@ -1295,7 +1299,7 @@ static long kgsl_ioctl_drawctxt_create(struct kgsl_device_private *dev_priv,
 	trace_kgsl_context_create(dev_priv->device, context, param->flags);
 	param->drawctxt_id = context->id;
 done:
-	if (result && context)
+	if (result && !IS_ERR(context))
 		kgsl_context_detach(context);
 
 	return result;