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>
This commit is contained in:
Jay Lubomirski 2007-06-27 14:10:09 -07:00 committed by Linus Torvalds
parent ddc80bd781
commit 2f4d4da8f8

View file

@ -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;
}