[Cbe-oss-dev] [PATCH 2/3] spufs: fix another off-by-one bug in mbox_read

[Arnd Bergmann]

On Tuesday 24 October 2006 21:53, Will Schmidt wrote:
> Hey Arnd,
>    just curiosity..   What was the behavior before this patch?   just
> leaving a few (0 - 3) characters behind?

It transfers more bytes than requested on a read. If you asked for
four bytes, you got eight.

Note: one nasty property of this file in spufs is that you can only
read multiples of four bytes in the first place, there is no way to
atomically put back a few bytes into the hardware register, so reading
less than four bytes returns -EINVAL. Asking for more than four
should return the largest possible multiple of four.

	Arnd <><