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| author | Stephen M. Cameron <scameron@beardog.cce.hp.com> | 2014-05-29 10:53:23 -0500 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-06-02 09:54:56 +0200 |
| commit | b3a52e791efd341a9a4e9065c667041c822661f0 (patch) | |
| tree | 313ac93ea68a60bf61bfb83c921599ac52a1ea3c /drivers/scsi/hpsa.c | |
| parent | 094963dad88c86f8f480c78992df03d916774c18 (diff) | |
| download | lwn-b3a52e791efd341a9a4e9065c667041c822661f0.tar.gz lwn-b3a52e791efd341a9a4e9065c667041c822661f0.zip | |
hpsa: avoid unnecessary readl on every command submission
for controllers which support either of the ioaccel transport methods.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi/hpsa.c')
| -rw-r--r-- | drivers/scsi/hpsa.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 3b70e66838ad..3e501df02e35 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -7330,6 +7330,13 @@ static void hpsa_enter_performant_mode(struct ctlr_info *h, u32 trans_support) * 10 = 6 s/g entry or 24k */ + /* If the controller supports either ioaccel method then + * we can also use the RAID stack submit path that does not + * perform the superfluous readl() after each command submission. + */ + if (trans_support & (CFGTBL_Trans_io_accel1 | CFGTBL_Trans_io_accel2)) + access = SA5_performant_access_no_read; + /* Controller spec: zero out this buffer. */ for (i = 0; i < h->nreply_queues; i++) memset(h->reply_queue[i].head, 0, h->reply_queue_size); |