Rate-limit usblp printer error status messages.
I unplugged my USB printer and almost instantly got several hundred
of these in my kernel message log:
drivers/usb/class/usblp.c: usblp0: error -19 reading printer status
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
 
        error = usblp_read_status (usblp, usblp->statusbuf);
        if (error < 0) {
-               err("usblp%d: error %d reading printer status",
-                       usblp->minor, error);
+               if (printk_ratelimit())
+                       err("usblp%d: error %d reading printer status",
+                               usblp->minor, error);
                return 0;
        }
 
 
                        case LPGETSTATUS:
                                if (usblp_read_status(usblp, usblp->statusbuf)) {
-                                       err("usblp%d: failed reading printer status", usblp->minor);
+                                       if (printk_ratelimit())
+                                               err("usblp%d: failed reading printer status",
+                                                       usblp->minor);
                                        retval = -EIO;
                                        goto done;
                                }