diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2017-11-07 11:39:56 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-07 15:34:08 +0100 |
| commit | 15081e85cca45e495144eb0c108926e629fde486 (patch) | |
| tree | e9917576ce63d0207da7d19b7892cd421e03a90e | |
| parent | 12f28144cf2cf69e1520e238eee7c384719ca44b (diff) | |
| download | linux-15081e85cca45e495144eb0c108926e629fde486.tar.bz2 | |
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 <arnd@arndb.de>
Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/usbip/vudc_dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
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) |