[U-Boot] [PATCH] kirkwood_egiga: bugfix: add DMA sequence points
Albert Aribaud
albert.aribaud at free.fr
Sat Jul 10 10:37:05 CEST 2010
Insert isb() sequence points to ensure DMA descriptors
are filled in and set up before actual DMA occurs.
Signed-off-by: Albert Aribaud <albert.aribaud at free.fr>
---
drivers/net/kirkwood_egiga.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/net/kirkwood_egiga.c b/drivers/net/kirkwood_egiga.c
index 932792e..9eca2f3 100644
--- a/drivers/net/kirkwood_egiga.c
+++ b/drivers/net/kirkwood_egiga.c
@@ -447,6 +447,8 @@ static int kwgbe_init(struct eth_device *dev)
/* Assignment of Rx CRDB of given RXUQ */
KWGBEREG_WR(regs->rxcdp[RXUQ], (u32) dkwgbe->p_rxdesc_curr);
+ /* ensure previous write is done before enabling Rx DMA */
+ isb();
/* Enable port Rx. */
KWGBEREG_WR(regs->rqc, (1 << RXUQ));
@@ -536,6 +538,9 @@ static int kwgbe_send(struct eth_device *dev, volatile void *dataptr,
p_txdesc->buf_ptr = (u8 *) p;
p_txdesc->byte_cnt = datasize;
+ /* ensure tx desc writes above are performed before we start Tx DMA */
+ isb();
+
/* Apply send command using zeroth TXUQ */
KWGBEREG_WR(regs->tcqdp[TXUQ], (u32) p_txdesc);
KWGBEREG_WR(regs->tqc, (1 << TXUQ));
--
1.6.4.4
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