[PATCH] amba-pl011: fix panic introduced by "clear pendinginterrupts"

From: Alessandro Rubini
Date: Mon Mar 26 2012 - 16:32:45 EST

patch 9b96fba, currently in linux-next, clears interrupts using
uap->port.membase that has not been assigned. My x86 system,
that uses a pci-to-amba bridge, panics with a message like:

BUG: unable to handle kernel NULL pointer dereference at 00000038
IP: [<c12c85ed>] pl011_probe+0x119/0x303

Signed-off-by: Alessandro Rubini <rubini@xxxxxxxxx>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@xxxxxx>
drivers/tty/serial/amba-pl011.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 2b4e981..38c992d 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1947,8 +1947,8 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)

/* Ensure interrupts from this UART are masked and cleared */
- writew(0, uap->port.membase + UART011_IMSC);
- writew(0xffff, uap->port.membase + UART011_ICR);
+ writew(0, base + UART011_IMSC);
+ writew(0xffff, base + UART011_ICR);

uap->vendor = vendor;
uap->lcrh_rx = vendor->lcrh_rx;
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