On Mon, 13 Jan 2014 11:07:28 +0800, Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx> wrote: > From IEEE 1275, there defined a standard 'status' property indicating the > operational status of one device. The 'status' property has four possible > values: 'okay/ok', 'disabled', 'fail' and 'fail-xxx'. > > If it is absent, that means the status of the device is unknown or okay. > > The __of_device_is_available checks the state of the 'status' property of > a device. If the property is absent or set to 'okay/ok', it returns 1. > Otherwise it returns 0. > > While in __of_device_is_available: > > status = of_get_property(device, "status", &statlen); > > if (status == NULL) > > return 1; > The status value returned from 'of_get_property()' will be NULL in two cases: > Firstly: the 'device' value (device node) is NULL. > Secondly: the 'status' property is actaully not exist. > > If the device node is NULL, the __of_device_is_available will return true, > that will mean the absent state of the 'status' property. > > So this add the device node check before checking the 'status' property's > state, and if the device node is not exist, 0 will be returned. > > Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx> Applied, thanks g. > --- > drivers/of/base.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index f807d0e..ba195fb 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -415,6 +415,9 @@ static int __of_device_is_available(const struct device_node *device) > const char *status; > int statlen; > > + if (!device) > + return 0; > + > status = __of_get_property(device, "status", &statlen); > if (status == NULL) > return 1; > -- > 1.8.4 > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
