From: Michael Büsch <m@bues.ch>
Date: Mon, 4 Jul 2011 17:51:11 +0000 (+0200)
Subject: b43: Add RX side DMA memory barrier
X-Git-Tag: accepted/tizen/common/20141203.182822~6192^2~12^2~42^2~251
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=73e6cdcf479ce3a8d33a726f0477473db35a4b2e;p=platform%2Fkernel%2Flinux-arm64.git

b43: Add RX side DMA memory barrier

This adds a memory barrier to ensure the writes to the ring memory
are committed before the DMA ring pointer is updated.
We do a similar thing on the TX side already.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index d02cf83..7a09a46 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -1600,6 +1600,7 @@ void b43_dma_rx(struct b43_dmaring *ring)
 		dma_rx(ring, &slot);
 		update_max_used_slots(ring, ++used_slots);
 	}
+	wmb();
 	ops->set_current_rxslot(ring, slot);
 	ring->current_slot = slot;
 }