V4L/DVB (4316): Check __must_check warnings

Check __must_check warnings for class_device_register and class_device_create_file

video_device_create_file was declared as a void, but instead should
return the int value of class_device_create_file.

Move the check from bttv-driver.c into v4l2-dev.h, because all other
callers of video_device_create_file must also be checked.

Replace the call to class_device_create_file in videodev.c with
video_device_create_file, as defined in v4l2-dev.h, so that the
return value of class_device_create_file will be checked.

Check the return value of class_device_register in videodev.c and
pvrusb2-sysfs.c

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 28 insertions, 5 deletions

diff --git a/drivers/media/video/pvrusb2/pvrusb2-sysfs.c b/drivers/media/video/pvrusb2/pvrusb2-sysfs.c
index 6af55a8b6f05..ef46d4f40cff 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-sysfs.c
+++ b/drivers/media/video/pvrusb2/pvrusb2-sysfs.c
@@ -600,6 +600,8 @@ static ssize_t debugcmd_store(struct class_device *,const char *,size_t count);
 static void pvr2_sysfs_add_debugifc(struct pvr2_sysfs *sfp)
 {
         struct pvr2_sysfs_debugifc *dip;
+        int ret;
+
         dip = kmalloc(sizeof(*dip),GFP_KERNEL);
         if (!dip) return;
         memset(dip,0,sizeof(*dip));
@@ -613,8 +615,14 @@ static void pvr2_sysfs_add_debugifc(struct pvr2_sysfs *sfp)
         dip->attr_debuginfo.attr.mode = S_IRUGO;
         dip->attr_debuginfo.show = debuginfo_show;
         sfp->debugifc = dip;
-        class_device_create_file(sfp->class_dev,&dip->attr_debugcmd);
-        class_device_create_file(sfp->class_dev,&dip->attr_debuginfo);
+        ret = class_device_create_file(sfp->class_dev,&dip->attr_debugcmd);
+        if (ret < 0)
+                printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
+                       __FUNCTION__, ret);
+        ret = class_device_create_file(sfp->class_dev,&dip->attr_debuginfo);
+        if (ret < 0)
+                printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
+                       __FUNCTION__, ret);
 }
 
 
@@ -709,6 +717,8 @@ static void class_dev_create(struct pvr2_sysfs *sfp,
 {
         struct usb_device *usb_dev;
         struct class_device *class_dev;
+        int ret;
+
         usb_dev = pvr2_hdw_get_dev(sfp->channel.hdw);
         if (!usb_dev) return;
         class_dev = kmalloc(sizeof(*class_dev),GFP_KERNEL);
@@ -733,20 +743,33 @@ static void class_dev_create(struct pvr2_sysfs *sfp,
 
         sfp->class_dev = class_dev;
         class_dev->class_data = sfp;
-        class_device_register(class_dev);
+        ret = class_device_register(class_dev);
+        if (ret) {
+                printk(KERN_ERR "%s: class_device_register failed\n",
+                       __FUNCTION__);
+                kfree(class_dev);
+                return;
+        }
 
         sfp->attr_v4l_minor_number.attr.owner = THIS_MODULE;
         sfp->attr_v4l_minor_number.attr.name = "v4l_minor_number";
         sfp->attr_v4l_minor_number.attr.mode = S_IRUGO;
         sfp->attr_v4l_minor_number.show = v4l_minor_number_show;
         sfp->attr_v4l_minor_number.store = NULL;
-        class_device_create_file(sfp->class_dev,&sfp->attr_v4l_minor_number);
+        ret = class_device_create_file(sfp->class_dev,&sfp->attr_v4l_minor_number);
+        if (ret < 0)
+                printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
+                       __FUNCTION__, ret);
+
         sfp->attr_unit_number.attr.owner = THIS_MODULE;
         sfp->attr_unit_number.attr.name = "unit_number";
         sfp->attr_unit_number.attr.mode = S_IRUGO;
         sfp->attr_unit_number.show = unit_number_show;
         sfp->attr_unit_number.store = NULL;
-        class_device_create_file(sfp->class_dev,&sfp->attr_unit_number);
+        ret = class_device_create_file(sfp->class_dev,&sfp->attr_unit_number);
+        if (ret < 0)
+                printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
+                       __FUNCTION__, ret);
 
         pvr2_sysfs_add_controls(sfp);
 #ifdef CONFIG_VIDEO_PVRUSB2_DEBUGIFC