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authorGreg Kroah-Hartman <gregkh@suse.de>2007-04-09 11:52:31 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2007-04-27 10:57:30 -0700
commit341487a837c02cbd674d4751061e7d098b0b8e98 (patch)
tree58166480d534a86f7b096b81572bd51c8dad031d /drivers/usb/core/devio.c
parentb7bb125dc3d0ca3f72c9116525ce0f018a9844e1 (diff)
USB: remove use of the bus rwsem, as it doesn't really protect anything.
The driver core stopped using the rwsem a long time ago, yet the USB core still grabbed the lock, thinking it protected something. This patch removes that useless use. Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.de> Cc: David Brownell <david-b@pacbell.net> Cc: linux-usb-devel <linux-usb-devel@lists.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core/devio.c')
-rw-r--r--drivers/usb/core/devio.c13
1 files changed, 0 insertions, 13 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 36e7a843bf9..fc3545ddb06 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -421,14 +421,11 @@ static int claimintf(struct dev_state *ps, unsigned int ifnum)
if (test_bit(ifnum, &ps->ifclaimed))
return 0;
- /* lock against other changes to driver bindings */
- down_write(&usb_bus_type.subsys.rwsem);
intf = usb_ifnum_to_if(dev, ifnum);
if (!intf)
err = -ENOENT;
else
err = usb_driver_claim_interface(&usbfs_driver, intf, ps);
- up_write(&usb_bus_type.subsys.rwsem);
if (err == 0)
set_bit(ifnum, &ps->ifclaimed);
return err;
@@ -444,8 +441,6 @@ static int releaseintf(struct dev_state *ps, unsigned int ifnum)
if (ifnum >= 8*sizeof(ps->ifclaimed))
return err;
dev = ps->dev;
- /* lock against other changes to driver bindings */
- down_write(&usb_bus_type.subsys.rwsem);
intf = usb_ifnum_to_if(dev, ifnum);
if (!intf)
err = -ENOENT;
@@ -453,7 +448,6 @@ static int releaseintf(struct dev_state *ps, unsigned int ifnum)
usb_driver_release_interface(&usbfs_driver, intf);
err = 0;
}
- up_write(&usb_bus_type.subsys.rwsem);
return err;
}
@@ -813,7 +807,6 @@ static int proc_getdriver(struct dev_state *ps, void __user *arg)
if (copy_from_user(&gd, arg, sizeof(gd)))
return -EFAULT;
- down_read(&usb_bus_type.subsys.rwsem);
intf = usb_ifnum_to_if(ps->dev, gd.interface);
if (!intf || !intf->dev.driver)
ret = -ENODATA;
@@ -822,7 +815,6 @@ static int proc_getdriver(struct dev_state *ps, void __user *arg)
sizeof(gd.driver));
ret = (copy_to_user(arg, &gd, sizeof(gd)) ? -EFAULT : 0);
}
- up_read(&usb_bus_type.subsys.rwsem);
return ret;
}
@@ -1351,15 +1343,12 @@ static int proc_ioctl(struct dev_state *ps, struct usbdevfs_ioctl *ctl)
/* disconnect kernel driver from interface */
case USBDEVFS_DISCONNECT:
-
- down_write(&usb_bus_type.subsys.rwsem);
if (intf->dev.driver) {
driver = to_usb_driver(intf->dev.driver);
dev_dbg (&intf->dev, "disconnect by usbfs\n");
usb_driver_release_interface(driver, intf);
} else
retval = -ENODATA;
- up_write(&usb_bus_type.subsys.rwsem);
break;
/* let kernel drivers try to (re)bind to the interface */
@@ -1371,7 +1360,6 @@ static int proc_ioctl(struct dev_state *ps, struct usbdevfs_ioctl *ctl)
/* talk directly to the interface's driver */
default:
- down_read(&usb_bus_type.subsys.rwsem);
if (intf->dev.driver)
driver = to_usb_driver(intf->dev.driver);
if (driver == NULL || driver->ioctl == NULL) {
@@ -1381,7 +1369,6 @@ static int proc_ioctl(struct dev_state *ps, struct usbdevfs_ioctl *ctl)
if (retval == -ENOIOCTLCMD)
retval = -ENOTTY;
}
- up_read(&usb_bus_type.subsys.rwsem);
}
/* cleanup and return */