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authorAndreas Oberritter <obi@linuxtv.org>2008-10-23 12:11:19 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2008-12-29 17:53:12 -0200
commit5dd3f3071070f5a306bdf8d474c80062f5691cba (patch)
treefc576a715c397ac5c5459006ea34a9ffac3d430b
parent568e9bb8d764300e1de81d49ae698cc970a511d8 (diff)
V4L/DVB (9361): Dynamic DVB minor allocation
Implement dynamic minor allocation for DVB, to allow more than four devices of the same type per adapter, based on drivers/usb/core/file.c. Add a new config option, DVB_DYNAMIC_MINORS, to make use of this feature, which defaults to no for backwards compatibility. Signed-off-by: Andreas Oberritter <obi@linuxtv.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/media/dvb/Kconfig13
-rw-r--r--drivers/media/dvb/dvb-core/dvbdev.c57
-rw-r--r--drivers/media/dvb/dvb-core/dvbdev.h1
3 files changed, 52 insertions, 19 deletions
diff --git a/drivers/media/dvb/Kconfig b/drivers/media/dvb/Kconfig
index 0bcd852576d..40ebde53b3c 100644
--- a/drivers/media/dvb/Kconfig
+++ b/drivers/media/dvb/Kconfig
@@ -2,6 +2,19 @@
# DVB device configuration
#
+config DVB_DYNAMIC_MINORS
+ bool "Dynamic DVB minor allocation"
+ depends on DVB_CORE
+ default n
+ help
+ If you say Y here, the DVB subsystem will use dynamic minor
+ allocation for any device that uses the DVB major number.
+ This means that you can have more than 4 of a single type
+ of device (like demuxes and frontends) per adapter, but udev
+ will be required to manage the device nodes.
+
+ If you are unsure about this, say N here.
+
menuconfig DVB_CAPTURE_DRIVERS
bool "DVB/ATSC adapters"
depends on DVB_CORE
diff --git a/drivers/media/dvb/dvb-core/dvbdev.c b/drivers/media/dvb/dvb-core/dvbdev.c
index a113744a56c..e363a3b5054 100644
--- a/drivers/media/dvb/dvb-core/dvbdev.c
+++ b/drivers/media/dvb/dvb-core/dvbdev.c
@@ -50,33 +50,27 @@ static const char * const dnames[] = {
"net", "osd"
};
+#ifdef CONFIG_DVB_DYNAMIC_MINORS
+#define MAX_DVB_MINORS 256
+#define DVB_MAX_IDS MAX_DVB_MINORS
+#else
#define DVB_MAX_IDS 4
#define nums2minor(num,type,id) ((num << 6) | (id << 4) | type)
#define MAX_DVB_MINORS (DVB_MAX_ADAPTERS*64)
+#endif
static struct class *dvb_class;
-static struct dvb_device* dvbdev_find_device (int minor)
-{
- struct dvb_adapter *adap;
-
- list_for_each_entry(adap, &dvb_adapter_list, list_head) {
- struct dvb_device *dev;
- list_for_each_entry(dev, &adap->device_list, list_head)
- if (nums2minor(adap->num, dev->type, dev->id) == minor)
- return dev;
- }
-
- return NULL;
-}
-
+static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
+static DECLARE_RWSEM(minor_rwsem);
static int dvb_device_open(struct inode *inode, struct file *file)
{
struct dvb_device *dvbdev;
lock_kernel();
- dvbdev = dvbdev_find_device (iminor(inode));
+ down_read(&minor_rwsem);
+ dvbdev = dvb_minors[iminor(inode)];
if (dvbdev && dvbdev->fops) {
int err = 0;
@@ -92,9 +86,11 @@ static int dvb_device_open(struct inode *inode, struct file *file)
file->f_op = fops_get(old_fops);
}
fops_put(old_fops);
+ up_read(&minor_rwsem);
unlock_kernel();
return err;
}
+ up_read(&minor_rwsem);
unlock_kernel();
return -ENODEV;
}
@@ -192,6 +188,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
struct dvb_device *dvbdev;
struct file_operations *dvbdevfops;
struct device *clsdev;
+ int minor;
int id;
mutex_lock(&dvbdev_register_lock);
@@ -231,6 +228,26 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
list_add_tail (&dvbdev->list_head, &adap->device_list);
+ down_write(&minor_rwsem);
+#ifdef CONFIG_DVB_DYNAMIC_MINORS
+ for (minor = 0; minor < MAX_DVB_MINORS; minor++)
+ if (dvb_minors[minor] == NULL)
+ break;
+
+ if (minor == MAX_DVB_MINORS) {
+ kfree(dvbdevfops);
+ kfree(dvbdev);
+ mutex_unlock(&dvbdev_register_lock);
+ return -EINVAL;
+ }
+#else
+ minor = nums2minor(adap->num, type, id);
+#endif
+
+ dvbdev->minor = minor;
+ dvb_minors[minor] = dvbdev;
+ up_write(&minor_rwsem);
+
mutex_unlock(&dvbdev_register_lock);
clsdev = device_create(dvb_class, adap->device,
@@ -243,8 +260,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
}
dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
- adap->num, dnames[type], id, nums2minor(adap->num, type, id),
- nums2minor(adap->num, type, id));
+ adap->num, dnames[type], id, minor, minor);
return 0;
}
@@ -256,8 +272,11 @@ void dvb_unregister_device(struct dvb_device *dvbdev)
if (!dvbdev)
return;
- device_destroy(dvb_class, MKDEV(DVB_MAJOR, nums2minor(dvbdev->adapter->num,
- dvbdev->type, dvbdev->id)));
+ down_write(&minor_rwsem);
+ dvb_minors[dvbdev->minor] = NULL;
+ up_write(&minor_rwsem);
+
+ device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
list_del (&dvbdev->list_head);
kfree (dvbdev->fops);
diff --git a/drivers/media/dvb/dvb-core/dvbdev.h b/drivers/media/dvb/dvb-core/dvbdev.h
index 574e336bac3..dca49cf962e 100644
--- a/drivers/media/dvb/dvb-core/dvbdev.h
+++ b/drivers/media/dvb/dvb-core/dvbdev.h
@@ -74,6 +74,7 @@ struct dvb_device {
struct file_operations *fops;
struct dvb_adapter *adapter;
int type;
+ int minor;
u32 id;
/* in theory, 'users' can vanish now,