Re: [PATCH] usb: Kconfig: make USB_ULPI_BUS select USB_COMMON

From: Peter Chen <hzpeterchen@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Peter Chen <peter.chen@nxp.com>, Felipe Balbi <balbi@kernel.org>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: Kconfig: make USB_ULPI_BUS select USB_COMMON
Date: Tue, 13 Sep 2016 15:19:42 +0800	[thread overview]
Message-ID: <20160913071942.GC30425@b29397-desktop> (raw)
In-Reply-To: <2868310.g9cFv2gbYX@wuerfel>

On Tue, Sep 13, 2016 at 09:04:08AM +0200, Arnd Bergmann wrote:
> On Tuesday, September 13, 2016 9:48:55 AM CEST Peter Chen wrote:
> > On Mon, Sep 12, 2016 at 05:36:23PM +0200, Arnd Bergmann wrote:
> > > Moving the CONFIG_USB_ULPI_BUS option to the top-level Kconfig file
> > > means that we can enable it without any of the other USB support,
> > > leading to a build error because Kbuild never enters the
> > > drivers/usb/common/ directory without CONFIG_USB_COMMON:
> > > 
> > > ERROR: "ulpi_unregister_driver" [drivers/phy/phy-tusb1210.ko] undefined!
> > > ERROR: "__ulpi_register_driver" [drivers/phy/phy-tusb1210.ko] undefined!
> > > ERROR: "ulpi_write" [drivers/phy/phy-tusb1210.ko] undefined!
> > > 
> > 
> > Thanks, Arnd. I have submitted the fix.
> > 
> > https://git.kernel.org/cgit/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=6406c3d226374c28d452b11db3b5ac241ce26191
> 
> I see you used 'depends on USB_COMMON' though instead of 'select USB_COMMON'.
> 
> This seems inconsistent with how we handle the other places after the patch
> I did earlier this year [see below].
> 
> It probably works fine for now, but having a mix of 'depends on' and 'select'
> can be confusing for users as well as create dependency loops that break
> the build.
> 
> 	Arnd

I just see below Kconfig entry at the same Kconfig
(drivers/usb/Kconfig), and forget your changes.

config USB_LED_TRIG
	bool "USB LED Triggers"
	depends on LEDS_CLASS && USB_COMMON && LEDS_TRIGGERS
	help
	  This option adds LED triggers for USB host and/or gadget activity.

	  Say Y here if you are working on a system with led-class supported
	  LEDs and you want to use them as activity indicators for USB host or
	  gadget.

Just grep it, some Kconfig still uses depends on for USB_COMMON, let me
change it together.

b29397@b29397-desktop:~/work/projects/usb$ find . -name Kconfig | xargs
grep -nr "USB_COMMON"
./drivers/phy/Kconfig:274:	select USB_COMMON
./drivers/usb/phy/Kconfig:72:	select USB_COMMON
./drivers/usb/Kconfig:32:config USB_COMMON
./drivers/usb/Kconfig:42:	select USB_COMMON
./drivers/usb/Kconfig:155:	depends on LEDS_CLASS && USB_COMMON &&
LEDS_TRIGGERS
./drivers/usb/gadget/Kconfig:18:	select USB_COMMON
./drivers/usb/usbip/Kconfig:3:	depends on USB_COMMON && NET

Peter

> 
> commit badf6d47f8a93098c6e05fdeb735b44b61877451
> Author: Arnd Bergmann <arnd@arndb.de>
> Date:   Wed Mar 23 17:45:08 2016 +0100
> 
>     usb: common: rework CONFIG_USB_COMMON logic
>     
>     The phy-am335x driver selects 'USB_COMMON', but all other drivers
>     use 'depends on' for that symbol, and it depends on USB || USB_GADGET
>     itself, which causes a Kconfig warning:
>     
>     warning: (AM335X_PHY_USB) selects USB_COMMON which has unmet direct dependencies (USB_SUPPORT && (USB || USB_GADGET))
>     
>     As suggested by Felipe Balbi, this turns the logic around, and makes
>     'USB_COMMON' selected by everything else that needs it, so we can
>     remove the dependencies.
>     
>     Fixes: 59f042f644c5 ("usb: phy: phy-am335x: bypass first VBUS sensing for host-only mode")
>     Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>     Acked-by: Felipe Balbi <balbi@kernel.org>
>     Reviewed-by: Peter Chen <peter.chen@nxp.com>
>     Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
> 
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 26566db09de0..e92b97cd6056 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -250,7 +250,8 @@ config PHY_SUN9I_USB
>  	tristate "Allwinner sun9i SoC USB PHY driver"
>  	depends on ARCH_SUNXI && HAS_IOMEM && OF
>  	depends on RESET_CONTROLLER
> -	depends on USB_COMMON
> +	depends on USB_SUPPORT
> +	select USB_COMMON
>  	select GENERIC_PHY
>  	help
>  	  Enable this to support the transceiver that is part of Allwinner
> diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
> index 8ed451dd651e..8689dcba5201 100644
> --- a/drivers/usb/Kconfig
> +++ b/drivers/usb/Kconfig
> @@ -31,8 +31,6 @@ if USB_SUPPORT
>  
>  config USB_COMMON
>  	tristate
> -	default y
> -	depends on USB || USB_GADGET
>  
>  config USB_ARCH_HAS_HCD
>  	def_bool y
> @@ -41,6 +39,7 @@ config USB_ARCH_HAS_HCD
>  config USB
>  	tristate "Support for Host-side USB"
>  	depends on USB_ARCH_HAS_HCD
> +	select USB_COMMON
>  	select NLS  # for UTF-8 strings
>  	---help---
>  	  Universal Serial Bus (USB) is a specification for a serial bus
> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
> index af5d922a8f5d..2057add439f0 100644
> --- a/drivers/usb/gadget/Kconfig
> +++ b/drivers/usb/gadget/Kconfig
> @@ -15,6 +15,7 @@
>  
>  menuconfig USB_GADGET
>  	tristate "USB Gadget Support"
> +	select USB_COMMON
>  	select NLS
>  	help
>  	   USB is a master/slave protocol, organized with one master
> 

-- 

Best Regards,
Peter Chen