[PATCH] serial: Clear proper MPSC interrupt cause bits

["Mark A. Greer" <mgreer@mvista.com>]

From: Jay Lubomirski <jaylubo@motorola.com>

Don't clobber the interrupt cause bits for both MPSC controllers when
clearing the interrupt for one of them.  Just clear the one that is
supposed to be cleared.

Signed-off-by: Jay Lubomirski <jaylubo@motorola.com>
Acked-by: Mark A. Greer <mgreer@mvista.com>
---
 drivers/serial/mpsc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/serial/mpsc.c b/drivers/serial/mpsc.c
index d09f209..00924fe 100644
--- a/drivers/serial/mpsc.c
+++ b/drivers/serial/mpsc.c
@@ -503,7 +503,8 @@ mpsc_sdma_intr_ack(struct mpsc_port_info *pi)
 
 	if (pi->mirror_regs)
 		pi->shared_regs->SDMA_INTR_CAUSE_m = 0;
-	writel(0, pi->shared_regs->sdma_intr_base + SDMA_INTR_CAUSE);
+	writeb(0x00, pi->shared_regs->sdma_intr_base + SDMA_INTR_CAUSE +
+	       pi->port.line);
 	return;
 }