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authorPete Zaitcev <zaitcev@redhat.com>2007-08-13 22:50:13 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2007-10-12 14:55:14 -0700
commitfc401e697f8c00ad1178a6758e86e3881dfa3181 (patch)
treeb744e6b010f646b21c6185896141252c49d91de2 /drivers/usb/class/usblp.c
parent7b5cd5fefbe023625a7ff7604e8beb9a15a9efab (diff)
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: Pete Zaitcev <zaitcev@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/class/usblp.c')
-rw-r--r--drivers/usb/class/usblp.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 9696668e575..2c4a359355b 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -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;