Commit 8ec04a49 authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
Browse files

staging: comedi: jr3_pci: cope with jiffies wraparound 



The timer expiry routine `jr3_pci_poll_dev()` checks for expiry by
checking whether the absolute value of `jiffies` (stored in local
variable `now`) is greater than the expected expiry time in jiffy units.
This will fail when `jiffies` wraps around.  Also, it seems to make
sense to handle the expiry one jiffy earlier than the current test.  Use
`time_after_eq()` to check for expiry.

Cc: <stable@vger.kernel.org> # 3.15+
Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 45292be0

drivers/staging/comedi/drivers/jr3_pci.c

+1 −1
Original line number Diff line number Diff line
@@ -611,7 +611,7 @@ static void jr3_pci_poll_dev(unsigned long data) 
		s = &dev->subdevices[i];

		spriv = s->private;



		if (now > spriv->next_time_min) {

		if (time_after_eq(now, spriv->next_time_min)) {

			struct jr3_pci_poll_delay sub_delay;



			sub_delay = jr3_pci_poll_subdevice(s);