[patch -next] V4L: ivtv: remove unneeded NULL checks

[patch -next] V4L: ivtv: remove unneeded NULL checks

[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.

Signed-off-by: Dan Carpenter <error27@gmail.com>

diff --git a/drivers/media/video/ivtv/ivtvfb.c b/drivers/media/video/ivtv/ivtvfb.c
index 2c2d862..be03a71 100644
--- a/drivers/media/video/ivtv/ivtvfb.c
+++ b/drivers/media/video/ivtv/ivtvfb.c
@@ -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);

Re: [patch -next] V4L: ivtv: remove unneeded NULL checks

[Andy Walls]

On Fri, 2010-07-23 at 12:12 +0200, Dan Carpenter wrote:
> 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.
> 
> Signed-off-by: Dan Carpenter <error27@gmail.com>

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


> diff --git a/drivers/media/video/ivtv/ivtvfb.c b/drivers/media/video/ivtv/ivtvfb.c
> index 2c2d862..be03a71 100644
> --- a/drivers/media/video/ivtv/ivtvfb.c
> +++ b/drivers/media/video/ivtv/ivtvfb.c
> @@ -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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Re: [patch -next] V4L: ivtv: remove unneeded NULL checks

[Dan Carpenter]

On Fri, Jul 23, 2010 at 07:46:47AM -0400, Andy Walls wrote:
> On Fri, 2010-07-23 at 12:12 +0200, Dan Carpenter wrote:
> > 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.
> > 
> > Signed-off-by: Dan Carpenter <error27@gmail.com>
> 
> 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