Commit 2f4d4da8 authored Jun 27, 2007 by Jay Lubomirski Committed by Linus Torvalds Jun 28, 2007

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>

parent ddc80bd7

drivers/serial/mpsc.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}

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