diff --git a/drivers/media/video/via-camera.c b/drivers/media/video/via-camera.c
index 85d3048c1d679dcc83cdf6a7afb8d0f6af1f15c2..bb7f17f2a33c20452ce9d6d37bbb29990215fe07 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)