Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit fc401e69 authored by Pete Zaitcev's avatar Pete Zaitcev Committed by Greg Kroah-Hartman
Browse files

usblp: mutex in usblp_check_status 



Add a mutex to protect the ->statusbuf. Not really an issue, because CUPS
is single-threaded when it talks to the printer, but I feel safer this way.
This should be deadlock-free, but I kept this as a separate patch in case
someone ends running a git bisect.

Signed-off-by: default avatarPete Zaitcev <zaitcev@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 7b5cd5fe

drivers/usb/class/usblp.c

+4 −3
Original line number Diff line number Diff line
@@ -345,16 +345,17 @@ static int usblp_check_status(struct usblp *usblp, int err) 
	unsigned char status, newerr = 0;

	int error;



	error = usblp_read_status (usblp, usblp->statusbuf);

	if (error < 0) {

	mutex_lock(&usblp->mut);

	if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {

		mutex_unlock(&usblp->mut);

		if (printk_ratelimit())

			printk(KERN_ERR

				"usblp%d: error %d reading printer status\n",

				usblp->minor, error);

		return 0;

	}



	status = *usblp->statusbuf;

	mutex_unlock(&usblp->mut);



	if (~status & LP_PERRORP)

		newerr = 3;