Re: [PATCH 1/2] usbip: fix off-by-one frame number calculation

From: Krzysztof Opasiak
Date: Tue Nov 07 2017 - 06:21:33 EST




On 11/07/2017 11:39 AM, Arnd Bergmann wrote:
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@xxxxxxxx>

Looks good to me:
Reviewed-by: Krzysztof Opasiak <k.opasiak@xxxxxxxxxxx>

--
Krzysztof Opasiak
Samsung R&D Institute Poland
Samsung Electronics