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    Subject[PATCH 4.4 13/56] staging: comedi: jr3_pci: cope with jiffies wraparound
    Date
    4.4-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Ian Abbott <abbotti@mev.co.uk>

    commit 8ec04a491825e08068e92bed0bba7821893b6433 upstream.

    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.

    Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/staging/comedi/drivers/jr3_pci.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- a/drivers/staging/comedi/drivers/jr3_pci.c
    +++ b/drivers/staging/comedi/drivers/jr3_pci.c
    @@ -610,7 +610,7 @@ static void jr3_pci_poll_dev(unsigned lo
    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);

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