diff options
| author | Greg Kroah-Hartman <gregkh@suse.de> | 2007-04-09 11:52:31 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-04-27 10:57:30 -0700 |
| commit | 341487a837c02cbd674d4751061e7d098b0b8e98 (patch) | |
| tree | 58166480d534a86f7b096b81572bd51c8dad031d /drivers/usb/core/devio.c | |
| parent | b7bb125dc3d0ca3f72c9116525ce0f018a9844e1 (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.c | 13 |
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 */ |