From 15081e85cca45e495144eb0c108926e629fde486 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 7 Nov 2017 11:39:56 +0100 Subject: usbip: fix off-by-one frame number calculation vgadget_get_frame returns a frame number from 0 to 2046, which may require an expensive division operation to wrap at one lower than the usual number. I can't see any reason for this, and all other drivers wrap at a power-of-two number. My best explanation is that it was a simple typo, so I'm changing the % modulo operator into a cheaper bitmask that the other drivers use, to make it wrap after 0x7ff rather than before it. Signed-off-by: Arnd Bergmann Reviewed-by: Krzysztof Opasiak Signed-off-by: Greg Kroah-Hartman --- drivers/usb/usbip/vudc_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/usb/usbip') diff --git a/drivers/usb/usbip/vudc_dev.c b/drivers/usb/usbip/vudc_dev.c index 0c07348820ea..16fb4f85a6f6 100644 --- a/drivers/usb/usbip/vudc_dev.c +++ b/drivers/usb/usbip/vudc_dev.c @@ -145,7 +145,7 @@ static int vgadget_get_frame(struct usb_gadget *_gadget) do_gettimeofday(&now); return ((now.tv_sec - udc->start_time.tv_sec) * 1000 + (now.tv_usec - udc->start_time.tv_usec) / 1000) - % 0x7FF; + & 0x7FF; } static int vgadget_set_selfpowered(struct usb_gadget *_gadget, int value) -- cgit