Patchwork typhoon: fix incorrect use of smp_wmb()

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Submitter David Dillow
Date March 4, 2010, 2:37 p.m.
Message ID <1267713436.2328.12.camel@lap75545.ornl.gov>
Download mbox | patch
Permalink /patch/46910/
State Accepted
Delegated to: David Miller
Headers show

Comments

David Dillow - March 4, 2010, 2:37 p.m.
The typhoon driver was incorrectly using smp_wmb() to order memory
accesses against IO to the NIC in a few instances. Use wmb() instead,
which is required to actually order between memory types.

Signed-off-by: David Dillow <dave@thedillows.org>
---
This is against Linus's tree, which doesn't appear to have net-next in
it yet. It should apply with offsets, though. I can redo against
net-next if needed, but likely won't have quick access to that tree
until the weekend.


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David Miller - March 5, 2010, 10:01 p.m.
From: David Dillow <dave@thedillows.org>
Date: Thu, 04 Mar 2010 09:37:16 -0500

> The typhoon driver was incorrectly using smp_wmb() to order memory
> accesses against IO to the NIC in a few instances. Use wmb() instead,
> which is required to actually order between memory types.
> 
> Signed-off-by: David Dillow <dave@thedillows.org>

Applied.
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Patch

diff --git a/drivers/net/typhoon.c b/drivers/net/typhoon.c
index 39f1fc6..a192852 100644
--- a/drivers/net/typhoon.c
+++ b/drivers/net/typhoon.c
@@ -487,7 +487,7 @@  typhoon_hello(struct typhoon *tp)
 		typhoon_inc_cmd_index(&ring->lastWrite, 1);
 
 		INIT_COMMAND_NO_RESPONSE(cmd, TYPHOON_CMD_HELLO_RESP);
-		smp_wmb();
+		wmb();
 		iowrite32(ring->lastWrite, tp->ioaddr + TYPHOON_REG_CMD_READY);
 		spin_unlock(&tp->command_lock);
 	}
@@ -1321,13 +1321,15 @@  typhoon_init_interface(struct typhoon *tp)
 
 	tp->txlo_dma_addr = le32_to_cpu(iface->txLoAddr);
 	tp->card_state = Sleeping;
-	smp_wmb();
 
 	tp->offload = TYPHOON_OFFLOAD_IP_CHKSUM | TYPHOON_OFFLOAD_TCP_CHKSUM;
 	tp->offload |= TYPHOON_OFFLOAD_UDP_CHKSUM | TSO_OFFLOAD_ON;
 
 	spin_lock_init(&tp->command_lock);
 	spin_lock_init(&tp->state_lock);
+
+	/* Force the writes to the shared memory area out before continuing. */
+	wmb();
 }
 
 static void