From stern@rowland.harvard.edu Wed Nov 12 11:42:02 2008 From: Alan Stern Date: Tue, 4 Nov 2008 11:29:27 -0500 (EST) Subject: USB: change interface to usb_lock_device_for_reset() To: Greg KH Cc: Pete Zaitcev Message-ID: This patch (as1161) changes the interface to usb_lock_device_for_reset(). The existing interface is apparently not very clear, judging from the fact that several of its callers don't use it correctly. The new interface always returns 0 for success and it always requires the caller to unlock the device afterward. The new routine will not return immediately if it is called while the driver's probe method is running. Instead it will wait until the probe is over and the device has been unlocked. This shouldn't cause any problems; I don't know of any cases where drivers call usb_lock_device_for_reset() during probe. Signed-off-by: Alan Stern Cc: Pete Zaitcev Signed-off-by: Greg Kroah-Hartman --- drivers/block/ub.c | 11 +++++------ drivers/hid/usbhid/hid-core.c | 9 ++++----- drivers/media/video/pvrusb2/pvrusb2-hdw.c | 2 +- drivers/usb/core/usb.c | 23 +++++++---------------- drivers/usb/image/microtek.c | 11 +++++------ drivers/usb/storage/transport.c | 8 +++----- 6 files changed, 25 insertions(+), 39 deletions(-) --- a/drivers/block/ub.c +++ b/drivers/block/ub.c @@ -1579,7 +1579,7 @@ static void ub_reset_task(struct work_st struct ub_dev *sc = container_of(work, struct ub_dev, reset_work); unsigned long flags; struct ub_lun *lun; - int lkr, rc; + int rc; if (!sc->reset) { printk(KERN_WARNING "%s: Running reset unrequested\n", @@ -1597,10 +1597,11 @@ static void ub_reset_task(struct work_st } else if (sc->dev->actconfig->desc.bNumInterfaces != 1) { ; } else { - if ((lkr = usb_lock_device_for_reset(sc->dev, sc->intf)) < 0) { + rc = usb_lock_device_for_reset(sc->dev, sc->intf); + if (rc < 0) { printk(KERN_NOTICE "%s: usb_lock_device_for_reset failed (%d)\n", - sc->name, lkr); + sc->name, rc); } else { rc = usb_reset_device(sc->dev); if (rc < 0) { @@ -1608,9 +1609,7 @@ static void ub_reset_task(struct work_st "usb_lock_device_for_reset failed (%d)\n", sc->name, rc); } - - if (lkr) - usb_unlock_device(sc->dev); + usb_unlock_device(sc->dev); } } --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -102,7 +102,7 @@ static void hid_reset(struct work_struct struct usbhid_device *usbhid = container_of(work, struct usbhid_device, reset_work); struct hid_device *hid = usbhid->hid; - int rc_lock, rc = 0; + int rc = 0; if (test_bit(HID_CLEAR_HALT, &usbhid->iofl)) { dev_dbg(&usbhid->intf->dev, "clear halt\n"); @@ -113,11 +113,10 @@ static void hid_reset(struct work_struct else if (test_bit(HID_RESET_PENDING, &usbhid->iofl)) { dev_dbg(&usbhid->intf->dev, "resetting device\n"); - rc = rc_lock = usb_lock_device_for_reset(hid_to_usb_dev(hid), usbhid->intf); - if (rc_lock >= 0) { + rc = usb_lock_device_for_reset(hid_to_usb_dev(hid), usbhid->intf); + if (rc == 0) { rc = usb_reset_device(hid_to_usb_dev(hid)); - if (rc_lock) - usb_unlock_device(hid_to_usb_dev(hid)); + usb_unlock_device(hid_to_usb_dev(hid)); } clear_bit(HID_RESET_PENDING, &usbhid->iofl); } --- a/drivers/media/video/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/video/pvrusb2/pvrusb2-hdw.c @@ -3655,7 +3655,7 @@ void pvr2_hdw_device_reset(struct pvr2_h int ret; pvr2_trace(PVR2_TRACE_INIT,"Performing a device reset..."); ret = usb_lock_device_for_reset(hdw->usb_dev,NULL); - if (ret == 1) { + if (ret == 0) { ret = usb_reset_device(hdw->usb_dev); usb_unlock_device(hdw->usb_dev); } else { --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -513,10 +513,7 @@ EXPORT_SYMBOL_GPL(usb_put_intf); * disconnect; in some drivers (such as usb-storage) the disconnect() * or suspend() method will block waiting for a device reset to complete. * - * Returns a negative error code for failure, otherwise 1 or 0 to indicate - * that the device will or will not have to be unlocked. (0 can be - * returned when an interface is given and is BINDING, because in that - * case the driver already owns the device lock.) + * Returns a negative error code for failure, otherwise 0. */ int usb_lock_device_for_reset(struct usb_device *udev, const struct usb_interface *iface) @@ -527,16 +524,9 @@ int usb_lock_device_for_reset(struct usb return -ENODEV; if (udev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; - if (iface) { - switch (iface->condition) { - case USB_INTERFACE_BINDING: - return 0; - case USB_INTERFACE_BOUND: - break; - default: - return -EINTR; - } - } + if (iface && (iface->condition == USB_INTERFACE_UNBINDING || + iface->condition == USB_INTERFACE_UNBOUND)) + return -EINTR; while (usb_trylock_device(udev) != 0) { @@ -550,10 +540,11 @@ int usb_lock_device_for_reset(struct usb return -ENODEV; if (udev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; - if (iface && iface->condition != USB_INTERFACE_BOUND) + if (iface && (iface->condition == USB_INTERFACE_UNBINDING || + iface->condition == USB_INTERFACE_UNBOUND)) return -EINTR; } - return 1; + return 0; } EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); --- a/drivers/usb/image/microtek.c +++ b/drivers/usb/image/microtek.c @@ -350,17 +350,16 @@ static int mts_scsi_abort(struct scsi_cm static int mts_scsi_host_reset(struct scsi_cmnd *srb) { struct mts_desc* desc = (struct mts_desc*)(srb->device->host->hostdata[0]); - int result, rc; + int result; MTS_DEBUG_GOT_HERE(); mts_debug_dump(desc); - rc = usb_lock_device_for_reset(desc->usb_dev, desc->usb_intf); - if (rc < 0) - return FAILED; - result = usb_reset_device(desc->usb_dev); - if (rc) + result = usb_lock_device_for_reset(desc->usb_dev, desc->usb_intf); + if (result == 0) { + result = usb_reset_device(desc->usb_dev); usb_unlock_device(desc->usb_dev); + } return result ? FAILED : SUCCESS; } --- a/drivers/usb/storage/transport.c +++ b/drivers/usb/storage/transport.c @@ -1173,10 +1173,9 @@ int usb_stor_Bulk_reset(struct us_data * */ int usb_stor_port_reset(struct us_data *us) { - int result, rc_lock; + int result; - result = rc_lock = - usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); + result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); if (result < 0) US_DEBUGP("unable to lock device for reset: %d\n", result); else { @@ -1189,8 +1188,7 @@ int usb_stor_port_reset(struct us_data * US_DEBUGP("usb_reset_device returns %d\n", result); } - if (rc_lock) - usb_unlock_device(us->pusb_dev); + usb_unlock_device(us->pusb_dev); } return result; }