diff options
| -rw-r--r-- | drivers/usb/core/hcd.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 8969e42434b..c5a2f83991d 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -582,10 +582,12 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd) } /* The USB 2.0 spec says 256 ms. This is close enough and won't - * exceed that limit if HZ is 100. */ + * exceed that limit if HZ is 100. The math is more clunky than + * maybe expected, this is to make sure that all timers for USB devices + * fire at the same time to give the CPU a break inbetween */ if (hcd->uses_new_polling ? hcd->poll_rh : (length == 0 && hcd->status_urb != NULL)) - mod_timer (&hcd->rh_timer, jiffies + msecs_to_jiffies(250)); + mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4)); } EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status); @@ -614,8 +616,8 @@ static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb) urb->hcpriv = hcd; /* indicate it's queued */ if (!hcd->uses_new_polling) - mod_timer (&hcd->rh_timer, jiffies + - msecs_to_jiffies(250)); + mod_timer (&hcd->rh_timer, + (jiffies/(HZ/4) + 1) * (HZ/4)); /* If a status change has already occurred, report it ASAP */ else if (hcd->poll_pending) |