]> git.proxmox.com Git - mirror_ubuntu-disco-kernel.git/commit
Input: ad7877 - keep dma rx buffers in seperate cache lines
authorOskar Schirmer <os@emlix.com>
Thu, 13 May 2010 07:42:23 +0000 (00:42 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Thu, 13 May 2010 07:43:32 +0000 (00:43 -0700)
commit3843384a055496dfed3c93ae883d964d8290fdab
treee60dfe169cd2a6bf83c7cb6d362c39a336b3798e
parentef110b24e28f36620f63dab94708a17c7e267358
Input: ad7877 - keep dma rx buffers in seperate cache lines

With dma based spi transmission, data corruption is observed
occasionally. With dma buffers located right next to msg and
xfer fields, cache lines correctly flushed in preparation for
dma usage may be polluted again when writing to fields in the
same cache line.

Make sure cache fields used with dma do not share cache lines
with fields changed during dma handling. As both fields are part
of a struct that is allocated via kzalloc, thus cache aligned,
moving the fields to the 1st position and insert padding for
alignment does the job.

Signed-off-by: Oskar Schirmer <os@emlix.com>
Signed-off-by: Daniel Glöckner <dg@emlix.com>
Signed-off-by: Oliver Schneidewind <osw@emlix.com>
Signed-off-by: Johannes Weiner <jw@emlix.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
[dtor@mail.ru - changed to use ___cacheline_aligned as suggested
 by akpm]
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
drivers/input/touchscreen/ad7877.c