Hi Bingbu On 01/12/2020 03:12, Bingbu Cao wrote: > Daniel, thanks for your patch. > > On 11/30/20 9:31 PM, Daniel Scally wrote: >> Some types of fwnode_handle do not implement the device_is_available() >> check, such as those created by software_nodes. There isn't really a >> meaningful way to check for the availability of a device that doesn't >> actually exist, so if the check isn't implemented just assume that the >> "device" is present. >> >> Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> >> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx> >> --- >> Changes since RFC v3: >> >> patch introduced >> >> drivers/base/property.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/base/property.c b/drivers/base/property.c >> index 4c43d30145c6..a5ca2306796f 100644 >> --- a/drivers/base/property.c >> +++ b/drivers/base/property.c >> @@ -785,9 +785,14 @@ EXPORT_SYMBOL_GPL(fwnode_handle_put); >> /** >> * fwnode_device_is_available - check if a device is available for use >> * @fwnode: Pointer to the fwnode of the device. >> + * >> + * For fwnode node types that don't implement the .device_is_available() >> + * operation, this function returns true. >> */ >> bool fwnode_device_is_available(const struct fwnode_handle *fwnode) >> { >> + if (!fwnode_has_op(fwnode, device_is_available)) >> + return true; > blank line here? Sure thing - I'll add one in >> return fwnode_call_bool_op(fwnode, device_is_available); >> } >> EXPORT_SYMBOL_GPL(fwnode_device_is_available); >>