diff options
| author | Jonathan Nieder <jrnieder@gmail.com> | 2011-05-01 11:30:14 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-05-20 14:29:38 +0200 |
| commit | 344d6c6ba6ba5c4fede2f07adbd26d53109a2dd8 (patch) | |
| tree | e76f78428ccde8e7c294f23ce128728ce0afb3d6 | |
| parent | [media] cx88: hold device lock during sub-driver initialization (diff) | |
| download | linux-344d6c6ba6ba5c4fede2f07adbd26d53109a2dd8.tar.xz linux-344d6c6ba6ba5c4fede2f07adbd26d53109a2dd8.zip | |
[media] cx88: protect cx8802_devlist with a mutex
Add and use a mutex to protect the cx88-mpeg device list. Previously
the BKL prevented races.
Based on work by Ben Hutchings <ben@decadent.org.uk>.
Tested-by: Andi Huber <hobrom@gmx.at>
Tested-by: Marlon de Boer <marlon@hyves.nl>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| -rw-r--r-- | drivers/media/video/cx88/cx88-mpeg.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/media/video/cx88/cx88-mpeg.c b/drivers/media/video/cx88/cx88-mpeg.c index 455290011d4e..1a7b983f8297 100644 --- a/drivers/media/video/cx88/cx88-mpeg.c +++ b/drivers/media/video/cx88/cx88-mpeg.c @@ -78,6 +78,7 @@ static void flush_request_modules(struct cx8802_dev *dev) static LIST_HEAD(cx8802_devlist); +static DEFINE_MUTEX(cx8802_mutex); /* ------------------------------------------------------------------ */ static int cx8802_start_dma(struct cx8802_dev *dev, @@ -689,6 +690,8 @@ int cx8802_register_driver(struct cx8802_driver *drv) return err; } + mutex_lock(&cx8802_mutex); + list_for_each_entry(dev, &cx8802_devlist, devlist) { printk(KERN_INFO "%s/2: subsystem: %04x:%04x, board: %s [card=%d]\n", @@ -698,8 +701,10 @@ int cx8802_register_driver(struct cx8802_driver *drv) /* Bring up a new struct for each driver instance */ driver = kzalloc(sizeof(*drv),GFP_KERNEL); - if (driver == NULL) - return -ENOMEM; + if (driver == NULL) { + err = -ENOMEM; + goto out; + } /* Snapshot of the driver registration data */ drv->core = dev->core; @@ -722,7 +727,10 @@ int cx8802_register_driver(struct cx8802_driver *drv) mutex_unlock(&drv->core->lock); } - return i ? 0 : -ENODEV; + err = i ? 0 : -ENODEV; +out: + mutex_unlock(&cx8802_mutex); + return err; } int cx8802_unregister_driver(struct cx8802_driver *drv) @@ -736,6 +744,8 @@ int cx8802_unregister_driver(struct cx8802_driver *drv) drv->type_id == CX88_MPEG_DVB ? "dvb" : "blackbird", drv->hw_access == CX8802_DRVCTL_SHARED ? "shared" : "exclusive"); + mutex_lock(&cx8802_mutex); + list_for_each_entry(dev, &cx8802_devlist, devlist) { printk(KERN_INFO "%s/2: subsystem: %04x:%04x, board: %s [card=%d]\n", @@ -762,6 +772,8 @@ int cx8802_unregister_driver(struct cx8802_driver *drv) mutex_unlock(&dev->core->lock); } + mutex_unlock(&cx8802_mutex); + return err; } @@ -799,7 +811,9 @@ static int __devinit cx8802_probe(struct pci_dev *pci_dev, goto fail_free; INIT_LIST_HEAD(&dev->drvlist); + mutex_lock(&cx8802_mutex); list_add_tail(&dev->devlist,&cx8802_devlist); + mutex_unlock(&cx8802_mutex); /* now autoload cx88-dvb or cx88-blackbird */ request_modules(dev); |