[PATCH] usb: usb_phy_gen: refine conditional declaration of usb_nop_xceiv_register

[PATCH] usb: usb_phy_gen: refine conditional declaration of usb_nop_xceiv_register

[Guenter Roeck]

Commit 3fa4d734 (usb: phy: rename nop_usb_xceiv => usb_phy_gen_xceiv)
changed the conditional around the declaration of usb_nop_xceiv_register
from
	#if defined(CONFIG_NOP_USB_XCEIV) ||
		(defined(CONFIG_NOP_USB_XCEIV_MODULE) && defined(MODULE))
to
	#if IS_ENABLED(CONFIG_NOP_USB_XCEIV)

While that looks the same, it is semantically different. The first expression
is true if CONFIG_NOP_USB_XCEIV is built as module and if the including
code is built as module. The second expression is true if code depending on
CONFIG_NOP_USB_XCEIV if built as module or into the kernel.

As a result, the arm:allmodconfig build fails with

arch/arm/mach-omap2/built-in.o: In function `omap3_evm_init':
arch/arm/mach-omap2/board-omap3evm.c:703: undefined reference to
	`usb_nop_xceiv_register'

Fix the problem by reverting to the old conditional.

Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 include/linux/usb/usb_phy_gen_xceiv.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/usb/usb_phy_gen_xceiv.h b/include/linux/usb/usb_phy_gen_xceiv.h
index f9a7e7b..11d85b9 100644
--- a/include/linux/usb/usb_phy_gen_xceiv.h
+++ b/include/linux/usb/usb_phy_gen_xceiv.h
@@ -12,7 +12,7 @@ struct usb_phy_gen_xceiv_platform_data {
 	unsigned int needs_reset:1;
 };
 
-#if IS_ENABLED(CONFIG_NOP_USB_XCEIV)
+#if defined(CONFIG_NOP_USB_XCEIV) || (defined(CONFIG_NOP_USB_XCEIV_MODULE) && defined(MODULE))
 /* sometimes transceivers are accessed only through e.g. ULPI */
 extern void usb_nop_xceiv_register(void);
 extern void usb_nop_xceiv_unregister(void);
-- 
1.7.9.7

Re: [PATCH] usb: usb_phy_gen: refine conditional declaration of usb_nop_xceiv_register

[Josh Boyer]

On Wed, Oct 16, 2013 at 07:18:41PM -0700, Guenter Roeck wrote:
> Commit 3fa4d734 (usb: phy: rename nop_usb_xceiv => usb_phy_gen_xceiv)
> changed the conditional around the declaration of usb_nop_xceiv_register
> from
> 	#if defined(CONFIG_NOP_USB_XCEIV) ||
> 		(defined(CONFIG_NOP_USB_XCEIV_MODULE) && defined(MODULE))
> to
> 	#if IS_ENABLED(CONFIG_NOP_USB_XCEIV)
> 
> While that looks the same, it is semantically different. The first expression
> is true if CONFIG_NOP_USB_XCEIV is built as module and if the including
> code is built as module. The second expression is true if code depending on
> CONFIG_NOP_USB_XCEIV if built as module or into the kernel.
> 
> As a result, the arm:allmodconfig build fails with
> 
> arch/arm/mach-omap2/built-in.o: In function `omap3_evm_init':
> arch/arm/mach-omap2/board-omap3evm.c:703: undefined reference to
> 	`usb_nop_xceiv_register'
> 
> Fix the problem by reverting to the old conditional.
> 
> Cc: Josh Boyer <jwboyer@redhat.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

I'm not entirely sure why I was CC'd on this one, but the patch looks
good to me.  I do wonder how many other uses of IS_ENABLED aren't taking
this into account though.

josh

> ---
>  include/linux/usb/usb_phy_gen_xceiv.h |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/usb/usb_phy_gen_xceiv.h b/include/linux/usb/usb_phy_gen_xceiv.h
> index f9a7e7b..11d85b9 100644
> --- a/include/linux/usb/usb_phy_gen_xceiv.h
> +++ b/include/linux/usb/usb_phy_gen_xceiv.h
> @@ -12,7 +12,7 @@ struct usb_phy_gen_xceiv_platform_data {
>  	unsigned int needs_reset:1;
>  };
>  
> -#if IS_ENABLED(CONFIG_NOP_USB_XCEIV)
> +#if defined(CONFIG_NOP_USB_XCEIV) || (defined(CONFIG_NOP_USB_XCEIV_MODULE) && defined(MODULE))
>  /* sometimes transceivers are accessed only through e.g. ULPI */
>  extern void usb_nop_xceiv_register(void);
>  extern void usb_nop_xceiv_unregister(void);
> -- 
> 1.7.9.7
> 

Re: [PATCH] usb: usb_phy_gen: refine conditional declaration of usb_nop_xceiv_register

[Guenter Roeck]

On Thu, Oct 17, 2013 at 01:25:48PM -0400, Josh Boyer wrote:
> On Wed, Oct 16, 2013 at 07:18:41PM -0700, Guenter Roeck wrote:
> > Commit 3fa4d734 (usb: phy: rename nop_usb_xceiv => usb_phy_gen_xceiv)
> > changed the conditional around the declaration of usb_nop_xceiv_register
> > from
> > 	#if defined(CONFIG_NOP_USB_XCEIV) ||
> > 		(defined(CONFIG_NOP_USB_XCEIV_MODULE) && defined(MODULE))
> > to
> > 	#if IS_ENABLED(CONFIG_NOP_USB_XCEIV)
> > 
> > While that looks the same, it is semantically different. The first expression
> > is true if CONFIG_NOP_USB_XCEIV is built as module and if the including
> > code is built as module. The second expression is true if code depending on
> > CONFIG_NOP_USB_XCEIV if built as module or into the kernel.
> > 
> > As a result, the arm:allmodconfig build fails with
> > 
> > arch/arm/mach-omap2/built-in.o: In function `omap3_evm_init':
> > arch/arm/mach-omap2/board-omap3evm.c:703: undefined reference to
> > 	`usb_nop_xceiv_register'
> > 
> > Fix the problem by reverting to the old conditional.
> > 
> > Cc: Josh Boyer <jwboyer@redhat.com>
> > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> 
> I'm not entirely sure why I was CC'd on this one, but the patch looks
> good to me.  I do wonder how many other uses of IS_ENABLED aren't taking
> this into account though.
> 
Unless I am wrong, you submitted a different patch to fix the same problem,
which went nowhere, so I figured it was appropriate to Cc: you on this one.
If not, my apologies.

As for other use cases of IS_ENABLED, agreed, that may be an ongoing concern. 
That will have to be addressed individually, though.

Thanks,
Guenter

Re: [PATCH] usb: usb_phy_gen: refine conditional declaration of usb_nop_xceiv_register

[Josh Boyer]

On Thu, Oct 17, 2013 at 01:31:47PM -0700, Guenter Roeck wrote:
> On Thu, Oct 17, 2013 at 01:25:48PM -0400, Josh Boyer wrote:
> > On Wed, Oct 16, 2013 at 07:18:41PM -0700, Guenter Roeck wrote:
> > > Commit 3fa4d734 (usb: phy: rename nop_usb_xceiv => usb_phy_gen_xceiv)
> > > changed the conditional around the declaration of usb_nop_xceiv_register
> > > from
> > > 	#if defined(CONFIG_NOP_USB_XCEIV) ||
> > > 		(defined(CONFIG_NOP_USB_XCEIV_MODULE) && defined(MODULE))
> > > to
> > > 	#if IS_ENABLED(CONFIG_NOP_USB_XCEIV)
> > > 
> > > While that looks the same, it is semantically different. The first expression
> > > is true if CONFIG_NOP_USB_XCEIV is built as module and if the including
> > > code is built as module. The second expression is true if code depending on
> > > CONFIG_NOP_USB_XCEIV if built as module or into the kernel.
> > > 
> > > As a result, the arm:allmodconfig build fails with
> > > 
> > > arch/arm/mach-omap2/built-in.o: In function `omap3_evm_init':
> > > arch/arm/mach-omap2/board-omap3evm.c:703: undefined reference to
> > > 	`usb_nop_xceiv_register'
> > > 
> > > Fix the problem by reverting to the old conditional.
> > > 
> > > Cc: Josh Boyer <jwboyer@redhat.com>
> > > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> > 
> > I'm not entirely sure why I was CC'd on this one, but the patch looks
> > good to me.  I do wonder how many other uses of IS_ENABLED aren't taking
> > this into account though.
> > 
> Unless I am wrong, you submitted a different patch to fix the same problem,
> which went nowhere, so I figured it was appropriate to Cc: you on this one.
> If not, my apologies.

Ah, so I did!  Amazing what I can forget in a month.

> As for other use cases of IS_ENABLED, agreed, that may be an ongoing concern. 
> That will have to be addressed individually, though.

Yep.

josh