Add memory barriers to kwgbe_send/recv
kwgbe_send/recv both have loops waiting for the hardware to set a bit.
GCC 4.3.3 cleverly optimizes this to ... a while(1); loop. This patch
introduces memory barriers to force re-loading of the transmit descriptor.
mb() wasn't defined for arm, but perhaps it should?
Signed-off-by: Simon Kagstrom <simon.kagst...@netinsight.net>
---
drivers/net/kirkwood_egiga.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/drivers/net/kirkwood_egiga.c b/drivers/net/kirkwood_egiga.c
index 3c5db19..abedf77 100644
--- a/drivers/net/kirkwood_egiga.c
+++ b/drivers/net/kirkwood_egiga.c
@@ -513,6 +513,8 @@ static int kwgbe_send(struct eth_device *dev, volatile void
*dataptr,
printf("Err..(%s) in xmit packet\n", __FUNCTION__);
return -1;
}
+ /* Memory barrier to see to it that cmd_sts is re-read */
+ asm volatile("" : : : "memory");
};
return 0;
}
@@ -531,6 +533,8 @@ static int kwgbe_recv(struct eth_device *dev)
debug("%s time out...\n", __FUNCTION__);
return -1;
}
+ /* Memory barrier to see to it that cmd_sts is re-read */
+ asm volatile("" : : : "memory");
} while (p_rxdesc_curr->cmd_sts & KWGBE_BUFFER_OWNED_BY_DMA);
if (p_rxdesc_curr->byte_cnt != 0) {
--
1.6.0.4
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