diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c index 5c00d79ac7a10b89ade256894e83444bf3d17ac1..c9560d8ba3cb1483a53691240662cf9aa822bcb3 100644 --- a/drivers/usb/class/usblp.c +++ b/drivers/usb/class/usblp.c @@ -1327,14 +1327,17 @@ static int usblp_set_protocol(struct usblp *usblp, int protocol) if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL) return -EINVAL; - alts = usblp->protocol[protocol].alt_setting; - if (alts < 0) - return -EINVAL; - r = usb_set_interface(usblp->dev, usblp->ifnum, alts); - if (r < 0) { - printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n", - alts, usblp->ifnum); - return r; + /* Don't unnecessarily set the interface if there's a single alt. */ + if (usblp->intf->num_altsetting > 1) { + alts = usblp->protocol[protocol].alt_setting; + if (alts < 0) + return -EINVAL; + r = usb_set_interface(usblp->dev, usblp->ifnum, alts); + if (r < 0) { + printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n", + alts, usblp->ifnum); + return r; + } } usblp->bidir = (usblp->protocol[protocol].epread != NULL);