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V4L: ivtv: remove unneeded NULL checks

PATCH In review Dan Carpenter 2 participants 3 messages Jul 23, 2010

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#0 lore raw

PATCH 1/1 V4L: ivtv: remove unneeded NULL checks

In ivtvfb_callback_cleanup() we dereference "itv" before checking that it's NULL. "itv" is assigned with container_of() which basically never returns a NULL pointer so the check is pointless. I removed it, along with a similar check in ivtvfb_callback_init().

I considered adding a check for v4l2_dev, but I looked at the code and I don't think that can be NULL either.

drivers/media/video/ivtv/ivtvfb.c +2 -2
index 2c2d862..be03a71 100644
@@ -1239,7 +1239,7 @@ static int __init ivtvfb_callback_init(struct device *dev, void *p)
 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 	struct ivtv *itv = container_of(v4l2_dev, struct ivtv, v4l2_dev);
 
-	if (itv && (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT)) {
+	if (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT) {
 		if (ivtvfb_init_card(itv) = 0) {
 			IVTVFB_INFO("Framebuffer registered on %s\n",
 					itv->v4l2_dev.name);
@@ -1255,7 +1255,7 @@ static int ivtvfb_callback_cleanup(struct device *dev, void *p)
 	struct ivtv *itv = container_of(v4l2_dev, struct ivtv, v4l2_dev);
 	struct osd_info *oi = itv->osd_info;
 
-	if (itv && (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT)) {
+	if (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT) {
 		if (unregister_framebuffer(&itv->osd_info->ivtvfb_info)) {
 			IVTVFB_WARN("Framebuffer %d is in use, cannot unload\n",
 				       itv->instance);
#1 lore raw
Quoted 9 lines · Dan Carpenter

In ivtvfb_callback_cleanup() we dereference "itv" before checking that it's NULL. "itv" is assigned with container_of() which basically never returns a NULL pointer so the check is pointless. I removed it, along with a similar check in ivtvfb_callback_init().

I considered adding a check for v4l2_dev, but I looked at the code and I don't think that can be NULL either.

Hi Dan,

Thanks, but Jiri Slaby already caught this one:

https://patchwork.kernel.org/patch/112725/

I'm going to let Mauro pick up Jiri's patch out of patchwork.

Regards,
Andy

Quoted 26 lines
drivers/media/video/ivtv/ivtvfb.c +2 -3
index 2c2d862..be03a71 100644
@@ -1239,7 +1239,7 @@ static int __init ivtvfb_callback_init(struct device *dev, void *p)
 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 	struct ivtv *itv = container_of(v4l2_dev, struct ivtv, v4l2_dev);
 
-	if (itv && (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT)) {
+	if (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT) {
 		if (ivtvfb_init_card(itv) = 0) {
 			IVTVFB_INFO("Framebuffer registered on %s\n",
 					itv->v4l2_dev.name);
@@ -1255,7 +1255,7 @@ static int ivtvfb_callback_cleanup(struct device *dev, void *p)
 	struct ivtv *itv = container_of(v4l2_dev, struct ivtv, v4l2_dev);
 	struct osd_info *oi = itv->osd_info;
 
-	if (itv && (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT)) {
+	if (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT) {
 		if (unregister_framebuffer(&itv->osd_info->ivtvfb_info)) {
 			IVTVFB_WARN("Framebuffer %d is in use, cannot unload\n",
 				       itv->instance);
--

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#2 lore raw
Quoted 11 lines · Andy Walls
Quoted 9 lines · Dan Carpenter

In ivtvfb_callback_cleanup() we dereference "itv" before checking that it's NULL. "itv" is assigned with container_of() which basically never returns a NULL pointer so the check is pointless. I removed it, along with a similar check in ivtvfb_callback_init().

I considered adding a check for v4l2_dev, but I looked at the code and I don't think that can be NULL either.

Quoted 8 lines

Hi Dan,

Thanks, but Jiri Slaby already caught this one:

https://patchwork.kernel.org/patch/112725/

I'm going to let Mauro pick up Jiri's patch out of patchwork.

Wow. It's remarkable how similar they are even down to the change log.

regards,
dan carpenter