[PATCH 1/2] serial: PL011: Repair NULL pointer dereference

[Lee Jones]

The pl011 driver attempts to mask and clear UART interrupts
at probe time, which subsequently fail with a NULL pointer
dereference error. This is due to 'uap->port.membase' being
used uninitialised. This patch moves the offending lines
to a point of post-initialisation.

Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
 drivers/tty/serial/amba-pl011.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 0c65c9e..b5c1f0f 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1946,10 +1946,6 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 		goto unmap;
 	}
 
-	/* Ensure interrupts from this UART are masked and cleared */
-	writew(0, uap->port.membase + UART011_IMSC);
-	writew(0xffff, uap->port.membase + UART011_ICR);
-
 	uap->vendor = vendor;
 	uap->lcrh_rx = vendor->lcrh_rx;
 	uap->lcrh_tx = vendor->lcrh_tx;
@@ -1965,6 +1961,11 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 	uap->port.ops = &amba_pl011_pops;
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = i;
+
+	/* Ensure interrupts from this UART are masked and cleared */
+	writew(0, uap->port.membase + UART011_IMSC);
+	writew(0xffff, uap->port.membase + UART011_ICR);
+
 	pl011_dma_probe(uap);
 
 	snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
-- 
1.7.5.4