Re: [PATCH] usb: misc: onboard_usb_dev: introduce new config symbol for usb5744 SMBus support

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Sep 24, 2024 at 07:49:11PM +0530, Radhey Shyam Pandey wrote:
> Introduce new kernel config symbol for Microchip usb5744 SMBus programming
> support. Since usb5744 i2c initialization routine uses i2c SMBus APIs these
> APIs should only be invoked when kernel has I2C support. This new kernel
> config describes the dependency on I2C kernel support and fix the below
> build issues when USB_ONBOARD_DEV=y and CONFIG_I2C=m.
> 
> riscv64-linux-ld: drivers/usb/misc/onboard_usb_dev.o:
> undefined reference to `i2c_find_device_by_fwnode'
> drivers/usb/misc/onboard_usb_dev.c:408:(.text+0xb24): undefined
> reference to `i2c_smbus_write_block_data'
> <snip>
> 
> Parsing of the i2c-bus bus handle is not put under usb5744 kernel config
> check as the intention is to report an error when DT is configured for
> usb5744 SMBus support and kernel has USB_ONBOARD_DEV_USB5744 disabled.
> 
> Fixes: 6782311d04df ("usb: misc: onboard_usb_dev: add Microchip usb5744 SMBus programming support")
> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
> Suggested-by: Matthias Kaehlcke <matthias@kaehlcke.net>
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202409140539.3Axwv38m-lkp@intel.com/
> ---
>  drivers/usb/misc/Kconfig           | 11 +++++++++++
>  drivers/usb/misc/onboard_usb_dev.c |  6 ++++--
>  2 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
> index 50b86d531701..29976a93f122 100644
> --- a/drivers/usb/misc/Kconfig
> +++ b/drivers/usb/misc/Kconfig
> @@ -331,3 +331,14 @@ config USB_ONBOARD_DEV
>  	  this config will enable the driver and it will automatically
>  	  match the state of the USB subsystem. If this driver is a
>  	  module it will be called onboard_usb_dev.
> +
> +config USB_ONBOARD_DEV_USB5744
> +	bool "Onboard USB Microchip usb5744 hub with SMBus support"
> +	depends on (USB_ONBOARD_DEV && I2C=y) || (USB_ONBOARD_DEV=m && I2C=m)
> +	default y

"default y" is if you can not boot without this option enabled for all
Linux systems.  I doubt that is the case here :(

thanks,

greg k-h