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| author | Rusty Russell <rusty@rustcorp.com.au> | 2008-12-30 08:02:35 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2008-12-30 08:02:35 +1030 |
| commit | 33edcf133ba93ecba2e4b6472e97b689895d805c (patch) | |
| tree | 327d7a20acef64005e7c5ccbfa1265be28aeb6ac /drivers/net/enic/vnic_rq.h | |
| parent | be4d638c1597580ed2294d899d9f1a2cd10e462c (diff) | |
| parent | 3c92ec8ae91ecf59d88c798301833d7cf83f2179 (diff) | |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'drivers/net/enic/vnic_rq.h')
| -rw-r--r-- | drivers/net/enic/vnic_rq.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/net/enic/vnic_rq.h b/drivers/net/enic/vnic_rq.h index 82bfca67cc4d..fd0ef66d2e9f 100644 --- a/drivers/net/enic/vnic_rq.h +++ b/drivers/net/enic/vnic_rq.h @@ -132,8 +132,15 @@ static inline void vnic_rq_post(struct vnic_rq *rq, #define VNIC_RQ_RETURN_RATE 0xf /* keep 2^n - 1 */ #endif - if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) + if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) { + /* Adding write memory barrier prevents compiler and/or CPU + * reordering, thus avoiding descriptor posting before + * descriptor is initialized. Otherwise, hardware can read + * stale descriptor fields. + */ + wmb(); iowrite32(buf->index, &rq->ctrl->posted_index); + } } static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count) |