[PATCH v6 1/6] net: qla3xxx: Eliminate duplicate barriers on weakly-ordered archs
Sinan Kaya
okaya at codeaurora.org
Fri Mar 23 15:23:06 PDT 2018
Code includes wmb() 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 code to
wmb()
writel_relaxed()
mmiowb()
for multi-arch support.
Signed-off-by: Sinan Kaya <okaya at codeaurora.org>
---
drivers/net/ethernet/qlogic/qla3xxx.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/qlogic/qla3xxx.c b/drivers/net/ethernet/qlogic/qla3xxx.c
index 9e5264d..b48f761 100644
--- a/drivers/net/ethernet/qlogic/qla3xxx.c
+++ b/drivers/net/ethernet/qlogic/qla3xxx.c
@@ -1858,8 +1858,9 @@ static void ql_update_small_bufq_prod_index(struct ql3_adapter *qdev)
qdev->small_buf_release_cnt -= 8;
}
wmb();
- writel(qdev->small_buf_q_producer_index,
- &port_regs->CommonRegs.rxSmallQProducerIndex);
+ writel_relaxed(qdev->small_buf_q_producer_index,
+ &port_regs->CommonRegs.rxSmallQProducerIndex);
+ mmiowb();
}
}
--
2.7.4
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