V4L/DVB (8751): vivi: Fix some issues at vivi register routine
This patch fixes several small issues at vivi register routines:
1) minor and n_devs should be unsigned;
2) n_devs = 0 were not properly handled;
3) if n_devs specify a high number, the driver would just roll back and
won't register any device. The proper behaviour is to keep all succeded
devices registered;
4) both n_devs and minor were using 0 as permissions. Better to have
them with 0444.
With the current patch, if n_devs specify a very large value, it will
register all possible devices. For example, on a machine without any
other V4L drivers loaded, with this patch, we will have something like:
vivi: V4L2 device registered as /dev/video0
vivi: V4L2 device registered as /dev/video1
vivi: V4L2 device registered as /dev/video2
...
vivi: V4L2 device registered as /dev/video31
video_register_device_index: get_index failed
Video Technology Magazine Virtual Video Capture Board ver 0.5.0 successfully loaded.
5) The number of allocated devices on success is now kept at n_devs:
$ cat /sys/module/vivi/parameters/n_devs
32
Thanks to Henne <henne@nachtwindheim.de> for pointing that there were
some issues at vivi.
Cc: Henne <henne@nachtwindheim.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index 3518af0..f55d77d 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -1104,19 +1104,29 @@
Initialization and module stuff
------------------------------------------------------------------*/
+/* This routine allocates from 1 to n_devs virtual drivers.
+
+ The real maximum number of virtual drivers will depend on how many drivers
+ will succeed. This is limited to the maximum number of devices that
+ videodev supports. Since there are 64 minors for video grabbers, this is
+ currently the theoretical maximum limit. However, a further limit does
+ exist at videodev that forbids any driver to register more than 32 video
+ grabbers.
+ */
static int __init vivi_init(void)
{
int ret = -ENOMEM, i;
struct vivi_dev *dev;
struct video_device *vfd;
+ if (n_devs <= 0)
+ n_devs = 1;
+
for (i = 0; i < n_devs; i++) {
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
- if (NULL == dev)
+ if (!dev)
break;
- list_add_tail(&dev->vivi_devlist, &vivi_devlist);
-
/* init video dma queues */
INIT_LIST_HEAD(&dev->vidq.active);
init_waitqueue_head(&dev->vidq.wq);
@@ -1126,14 +1136,27 @@
mutex_init(&dev->mutex);
vfd = video_device_alloc();
- if (NULL == vfd)
+ if (!vfd) {
+ kfree(dev);
break;
+ }
*vfd = vivi_template;
ret = video_register_device(vfd, VFL_TYPE_GRABBER, video_nr);
- if (ret < 0)
+ if (ret < 0) {
+ video_device_release(vfd);
+ kfree(dev);
+
+ /* If some registers succeeded, keep driver */
+ if (i)
+ ret = 0;
+
break;
+ }
+
+ /* Now that everything is fine, let's add it to device list */
+ list_add_tail(&dev->vivi_devlist, &vivi_devlist);
snprintf(vfd->name, sizeof(vfd->name), "%s (%i)",
vivi_template.name, vfd->minor);
@@ -1149,11 +1172,16 @@
if (ret < 0) {
vivi_release();
printk(KERN_INFO "Error %d while loading vivi driver\n", ret);
- } else
+ } else {
printk(KERN_INFO "Video Technology Magazine Virtual Video "
"Capture Board ver %u.%u.%u successfully loaded.\n",
(VIVI_VERSION >> 16) & 0xFF, (VIVI_VERSION >> 8) & 0xFF,
VIVI_VERSION & 0xFF);
+
+ /* n_devs will reflect the actual number of allocated devices */
+ n_devs = i;
+ }
+
return ret;
}
@@ -1169,10 +1197,10 @@
MODULE_AUTHOR("Mauro Carvalho Chehab, Ted Walther and John Sokol");
MODULE_LICENSE("Dual BSD/GPL");
-module_param(video_nr, int, 0);
+module_param(video_nr, uint, 0444);
MODULE_PARM_DESC(video_nr, "video iminor start number");
-module_param(n_devs, int, 0);
+module_param(n_devs, uint, 0444);
MODULE_PARM_DESC(n_devs, "number of video devices to create");
module_param_named(debug, vivi_template.debug, int, 0444);