[PATCH v2] usb: gadget: legacy gadgets are optional

From: Romain Izard
Date: Thu Mar 09 2017 - 09:11:22 EST

With commit "usb: gadget: don't couple configfs to legacy gadgets"
it is possible to build a modular kernel with both built-in configfs
support and modular legacy gadget drivers.

But when building a kernel without modules, it is also necessary to be
able to build with configfs but without any legacy gadget driver.

Mark the choice for legacy gadget drivers as optional.

Fixes: bc49d1d17dcf ("usb: gadget: don't couple configfs to legacy gadgets")
Cc: <stable@xxxxxxxxxxxxxxx> # 4.9+
Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
changes in v2:
- Reword description

drivers/usb/gadget/Kconfig | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 8ad203296079..e157e9aa4f3d 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -212,7 +212,7 @@ config USB_F_TCM
# this first set of drivers all depend on bulk-capable hardware.

- tristate "USB functions configurable through configfs"
+ tristate "USB Gadget functions configurable through configfs"
A Linux USB "gadget" can be set up through configfs.
@@ -458,8 +458,9 @@ config USB_CONFIGFS_F_TCM
UAS utilizes the USB 3.0 feature called streams support.

- tristate "USB Gadget Drivers"
+ tristate "USB Gadget precomposed configurations"
default USB_ETH
+ optional
A Linux "Gadget Driver" talks to the USB Peripheral Controller
driver through the abstract "gadget" API. Some other operating
@@ -476,6 +477,12 @@ choice
not be able work with that controller, or might need to implement
a less common variant of a device class protocol.

+ The available choices each represent a single precomposed USB
+ gadget configuration. In the device model, each option contains
+ both the device instanciation as a child for a USB gadget
+ controller, and the relevant drivers for each function declared
+ by the device.
source "drivers/usb/gadget/legacy/Kconfig"