lkml.org 
[lkml]   [2018]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4 6/7] scsi: bnx2i: Eliminate duplicate barriers on weakly-ordered archs
Date
Code includes barrier() followed by writel(). writel() already has a
barrier
on some architectures like arm64.

This ends up CPU observing two barriers back to back before executing the
register write.

Since code already has an explicit barrier call, changing writel() to
writel_relaxed().

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
drivers/scsi/bnx2i/bnx2i_hwi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/bnx2i/bnx2i_hwi.c b/drivers/scsi/bnx2i/bnx2i_hwi.c
index 8f03a86..075735b 100644
--- a/drivers/scsi/bnx2i/bnx2i_hwi.c
+++ b/drivers/scsi/bnx2i/bnx2i_hwi.c
@@ -278,7 +278,7 @@ static void bnx2i_ring_sq_dbell(struct bnx2i_conn *bnx2i_conn, int count)
sq_db->prod_idx = ep->qp.sq_prod_idx;
bnx2i_ring_577xx_doorbell(bnx2i_conn);
} else
- writew(count, ep->qp.ctx_base + CNIC_SEND_DOORBELL);
+ writew_relaxed(count, ep->qp.ctx_base + CNIC_SEND_DOORBELL);

mmiowb(); /* flush posted PCI writes */
}
--
2.7.4
\
 
 \ /
  Last update: 2018-03-20 03:51    [W:0.177 / U:0.780 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site