[PATCH] USB: convert a bunch of USB semaphores to mutexes
the patch below converts a bunch of semaphores-used-as-mutex in the USB
code to mutexes
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/media/w9968cf.c b/drivers/usb/media/w9968cf.c
index 78cd1a5..b57dec3 100644
--- a/drivers/usb/media/w9968cf.c
+++ b/drivers/usb/media/w9968cf.c
@@ -47,6 +47,13 @@
#include "w9968cf.h"
#include "w9968cf_decoder.h"
+static struct w9968cf_vpp_t* w9968cf_vpp;
+static DECLARE_WAIT_QUEUE_HEAD(w9968cf_vppmod_wait);
+
+static LIST_HEAD(w9968cf_dev_list); /* head of V4L registered cameras list */
+static DEFINE_MUTEX(w9968cf_devlist_mutex); /* semaphore for list traversal */
+
+static DECLARE_RWSEM(w9968cf_disconnect); /* prevent races with open() */
/****************************************************************************
@@ -2418,7 +2425,7 @@
enum w9968cf_model_id mod_id,
const unsigned short dev_nr)
{
- init_MUTEX(&cam->fileop_sem);
+ mutex_init(&cam->fileop_mutex);
init_waitqueue_head(&cam->open);
spin_lock_init(&cam->urb_lock);
spin_lock_init(&cam->flist_lock);
@@ -2646,7 +2653,7 @@
--------------------------------------------------------------------------*/
static void w9968cf_release_resources(struct w9968cf_device* cam)
{
- down(&w9968cf_devlist_sem);
+ mutex_lock(&w9968cf_devlist_mutex);
DBG(2, "V4L device deregistered: /dev/video%d", cam->v4ldev->minor)
@@ -2657,7 +2664,7 @@
kfree(cam->control_buffer);
kfree(cam->data_buffer);
- up(&w9968cf_devlist_sem);
+ mutex_unlock(&w9968cf_devlist_mutex);
}
@@ -2677,14 +2684,14 @@
cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));
- down(&cam->dev_sem);
+ mutex_lock(&cam->dev_mutex);
if (cam->sensor == CC_UNKNOWN) {
DBG(2, "No supported image sensor has been detected by the "
"'ovcamchip' module for the %s (/dev/video%d). Make "
"sure it is loaded *before* (re)connecting the camera.",
symbolic(camlist, cam->id), cam->v4ldev->minor)
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
up_read(&w9968cf_disconnect);
return -ENODEV;
}
@@ -2693,11 +2700,11 @@
DBG(2, "%s (/dev/video%d) has been already occupied by '%s'",
symbolic(camlist, cam->id),cam->v4ldev->minor,cam->command)
if ((filp->f_flags & O_NONBLOCK)||(filp->f_flags & O_NDELAY)) {
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
up_read(&w9968cf_disconnect);
return -EWOULDBLOCK;
}
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
err = wait_event_interruptible_exclusive(cam->open,
cam->disconnected ||
!cam->users);
@@ -2709,7 +2716,7 @@
up_read(&w9968cf_disconnect);
return -ENODEV;
}
- down(&cam->dev_sem);
+ mutex_lock(&cam->dev_mutex);
}
DBG(5, "Opening '%s', /dev/video%d ...",
@@ -2738,7 +2745,7 @@
DBG(5, "Video device is open")
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
up_read(&w9968cf_disconnect);
return 0;
@@ -2746,7 +2753,7 @@
deallocate_memory:
w9968cf_deallocate_memory(cam);
DBG(2, "Failed to open the video device")
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
up_read(&w9968cf_disconnect);
return err;
}
@@ -2758,13 +2765,13 @@
cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));
- down(&cam->dev_sem); /* prevent disconnect() to be called */
+ mutex_lock(&cam->dev_mutex); /* prevent disconnect() to be called */
w9968cf_stop_transfer(cam);
if (cam->disconnected) {
w9968cf_release_resources(cam);
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
kfree(cam);
return 0;
}
@@ -2774,7 +2781,7 @@
wake_up_interruptible_nr(&cam->open, 1);
DBG(5, "Video device closed")
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
return 0;
}
@@ -2791,18 +2798,18 @@
if (filp->f_flags & O_NONBLOCK)
return -EWOULDBLOCK;
- if (down_interruptible(&cam->fileop_sem))
+ if (mutex_lock_interruptible(&cam->fileop_mutex))
return -ERESTARTSYS;
if (cam->disconnected) {
DBG(2, "Device not present")
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return -ENODEV;
}
if (cam->misconfigured) {
DBG(2, "The camera is misconfigured. Close and open it again.")
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return -EIO;
}
@@ -2817,11 +2824,11 @@
cam->frame[1].status == F_READY ||
cam->disconnected);
if (err) {
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return err;
}
if (cam->disconnected) {
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return -ENODEV;
}
@@ -2835,7 +2842,7 @@
if (copy_to_user(buf, fr->buffer, count)) {
fr->status = F_UNUSED;
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return -EFAULT;
}
*f_pos += count;
@@ -2844,7 +2851,7 @@
DBG(5, "%zu bytes read", count)
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return count;
}
@@ -2898,24 +2905,24 @@
cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));
- if (down_interruptible(&cam->fileop_sem))
+ if (mutex_lock_interruptible(&cam->fileop_mutex))
return -ERESTARTSYS;
if (cam->disconnected) {
DBG(2, "Device not present")
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return -ENODEV;
}
if (cam->misconfigured) {
DBG(2, "The camera is misconfigured. Close and open it again.")
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return -EIO;
}
err = w9968cf_v4l_ioctl(inode, filp, cmd, (void __user *)arg);
- up(&cam->fileop_sem);
+ mutex_unlock(&cam->fileop_mutex);
return err;
}
@@ -3502,8 +3509,8 @@
if (!cam)
return -ENOMEM;
- init_MUTEX(&cam->dev_sem);
- down(&cam->dev_sem);
+ mutex_init(&cam->dev_mutex);
+ mutex_lock(&cam->dev_mutex);
cam->usbdev = udev;
/* NOTE: a local copy is used to avoid possible race conditions */
@@ -3515,10 +3522,10 @@
simcams = W9968CF_SIMCAMS;
/* How many cameras are connected ? */
- down(&w9968cf_devlist_sem);
+ mutex_lock(&w9968cf_devlist_mutex);
list_for_each(ptr, &w9968cf_dev_list)
sc++;
- up(&w9968cf_devlist_sem);
+ mutex_unlock(&w9968cf_devlist_mutex);
if (sc >= simcams) {
DBG(2, "Device rejected: too many connected cameras "
@@ -3578,9 +3585,9 @@
w9968cf_configure_camera(cam, udev, mod_id, dev_nr);
/* Add a new entry into the list of V4L registered devices */
- down(&w9968cf_devlist_sem);
+ mutex_lock(&w9968cf_devlist_mutex);
list_add(&cam->v4llist, &w9968cf_dev_list);
- up(&w9968cf_devlist_sem);
+ mutex_unlock(&w9968cf_devlist_mutex);
dev_nr = (dev_nr < W9968CF_MAX_DEVICES-1) ? dev_nr+1 : 0;
w9968cf_turn_on_led(cam);
@@ -3588,7 +3595,7 @@
w9968cf_i2c_init(cam);
usb_set_intfdata(intf, cam);
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
return 0;
fail: /* Free unused memory */
@@ -3596,7 +3603,7 @@
kfree(cam->data_buffer);
if (cam->v4ldev)
video_device_release(cam->v4ldev);
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
kfree(cam);
return err;
}
@@ -3611,7 +3618,7 @@
if (cam) {
/* Prevent concurrent accesses to data */
- down(&cam->dev_sem);
+ mutex_lock(&cam->dev_mutex);
cam->disconnected = 1;
@@ -3630,7 +3637,7 @@
} else
w9968cf_release_resources(cam);
- up(&cam->dev_sem);
+ mutex_unlock(&cam->dev_mutex);
if (!cam->users)
kfree(cam);