[PATCH] viacam: Don't explode if pci_find_bus() returns NULL

[Jesper Juhl]

In the unlikely case that pci_find_bus() should return NULL
viacam_serial_is_enabled() is going to dereference a NULL pointer and
blow up. Better safe than sorry, so be defensive and check the
pointer.

Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
 drivers/media/video/via-camera.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

  Compile tested only. I don't have the hardware.

diff --git a/drivers/media/video/via-camera.c b/drivers/media/video/via-camera.c
index 85d3048..bb7f17f 100644
--- a/drivers/media/video/via-camera.c
+++ b/drivers/media/video/via-camera.c
@@ -1332,6 +1332,8 @@ static __devinit bool viacam_serial_is_enabled(void)
 	struct pci_bus *pbus = pci_find_bus(0, 0);
 	u8 cbyte;
 
+	if (!pbus)
+		return false;
 	pci_bus_read_config_byte(pbus, VIACAM_SERIAL_DEVFN,
 			VIACAM_SERIAL_CREG, &cbyte);
 	if ((cbyte & VIACAM_SERIAL_BIT) == 0)
-- 
1.7.6


-- 
Jesper Juhl <jj@xxxxxxxxxxxxx>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
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