Re: [PATCH v2 3/9] usb: dwc3: qcom: fix gadget-only builds

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Aug 04, 2022 at 05:09:55PM +0200, Johan Hovold wrote:
> A recent change added a dependency to the USB host stack and broke
> gadget-only builds of the driver.
> 
> Fixes: 6895ea55c385 ("usb: dwc3: qcom: Configure wakeup interrupts during suspend")
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
> 
> Changes in v2
>  - new patch
> 
>  drivers/usb/dwc3/dwc3-qcom.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index be2e3dd36440..e9364141661b 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -310,8 +310,11 @@ static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
>  	 * currently supports only 1 port per controller. So
>  	 * this is sufficient.
>  	 */
> +#ifdef CONFIG_USB
>  	udev = usb_hub_find_child(hcd->self.root_hub, 1);

If a gadget driver needs this for some reason, then the #ifdef should be
put in a .h file, not in a .c file.

But step back a minute and ask why a host-config-only function is being
called when a device is in gadget-only mode?  This feels like a
design/logic issue in this file, NOT something to paper over with a
#ifdef in a .c file

This implies that if this device is NOT in a host configuration, then
the suspend path of it is not configured properly at all, as why would
it be checking or caring about this at all if this is in gadget-only
mode?

Something else is wrong here, let's fix the root problem please.  Maybe
this driver should just never be built in gadget-only mode, as it is
never intended to support that option?

thanks,

greg k-h