[PATCH v4 08/17] drivers: net: cxgb: Eliminate duplicate barriers on weakly-ordered archs
From: Sinan Kaya <hidden>
Date: 2018-03-20 02:46:43
Also in:
linux-arm-kernel, linux-arm-msm, lkml
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 writel() to writel_relaxed(). Signed-off-by: Sinan Kaya <redacted> --- drivers/net/ethernet/chelsio/cxgb/sge.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/chelsio/cxgb/sge.c b/drivers/net/ethernet/chelsio/cxgb/sge.c
index 30de26e..57891bd6 100644
--- a/drivers/net/ethernet/chelsio/cxgb/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb/sge.c@@ -495,7 +495,7 @@ static struct sk_buff *sched_skb(struct sge *sge, struct sk_buff *skb, static inline void doorbell_pio(struct adapter *adapter, u32 val) { wmb(); - writel(val, adapter->regs + A_SG_DOORBELL); + writel_relaxed(val, adapter->regs + A_SG_DOORBELL); } /*
--
2.7.4