kirkwood_egiga: bugfix: add DMA sequence points
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@free.fr>
Acked-by: Prafulla Wadaskar <prafulla@marvell.com>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/drivers/net/kirkwood_egiga.c b/drivers/net/kirkwood_egiga.c
index 932792e..ea0c522 100644
--- a/drivers/net/kirkwood_egiga.c
+++ b/drivers/net/kirkwood_egiga.c
@@ -447,6 +447,8 @@
/* 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));
@@ -536,8 +538,13 @@
p_txdesc->buf_ptr = (u8 *) p;
p_txdesc->byte_cnt = datasize;
- /* Apply send command using zeroth TXUQ */
+ /* Set this tc desc as zeroth TXUQ */
KWGBEREG_WR(regs->tcqdp[TXUQ], (u32) p_txdesc);
+
+ /* ensure tx desc writes above are performed before we start Tx DMA */
+ isb();
+
+ /* Apply send command using zeroth TXUQ */
KWGBEREG_WR(regs->tqc, (1 << TXUQ));
/*