From 2f4d4da8f82c2598b8713f4a01f360f3751d90be Mon Sep 17 00:00:00 2001 From: Jay Lubomirski <jaylubo@motorola.com> Date: Wed, 27 Jun 2007 14:10:09 -0700 Subject: [PATCH] serial: clear proper MPSC interrupt cause bits The interrupt clearing code in mpsc_sdma_intr_ack() mistakenly clears the interrupt for both controllers instead of just the one its supposed to. This can result in the other controller appearing to hang because its interrupt was effectively lost. So, don't clear 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> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- 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 d09f2097d5b0..00924feaf621 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; } -- 2.20.1