[PATCH] ARM: at91: fix at91_suspend_entering_slow_clock link error

[Alexandre Belloni]

Hi,

On 09/06/2017 at 12:18:02 +0200, Arnd Bergmann wrote:
> When CONFIG_ARCH_AT91 is enabled, but none of the specific SoC support
> is in use, some at91 specific drivers fail to link:
> 
> drivers/tty/serial/atmel_serial.o: In function `atmel_serial_suspend':
> atmel_serial.c:(.text.atmel_serial_suspend+0x1e): undefined reference to `at91_suspend_entering_slow_clock'
> drivers/usb/host/ohci-at91.o: In function `ohci_hcd_at91_drv_suspend':
> ohci-at91.c:(.text.ohci_hcd_at91_drv_suspend+0x12): undefined reference to `at91_suspend_entering_slow_clock'
> drivers/usb/gadget/udc/at91_udc.o: In function `at91udc_suspend':
> at91_udc.c:(.text.at91udc_suspend+0x26): undefined reference to `at91_suspend_entering_slow_clock'
>

How you present it makes me think, that this was present for a while,
even before samv7 support was added. Am I wrong?

> This changes the at91_suspend_entering_slow_clock hack once more, adding
> an alternative inline implementation that is used exactly in those cases
> that don't provide the normal implementation.
> 
> Fixes: c1892c2379d2 ("ARM: at91: handle CONFIG_PM for armv7m configurations")
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> ---
>  arch/arm/mach-at91/samv7.c          | 9 ---------
>  include/linux/platform_data/atmel.h | 7 +++++++
>  2 files changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/samv7.c b/arch/arm/mach-at91/samv7.c
> index 910f0c68db62..11386f190c83 100644
> --- a/arch/arm/mach-at91/samv7.c
> +++ b/arch/arm/mach-at91/samv7.c
> @@ -15,15 +15,6 @@
>  #include <asm/system_misc.h>
>  #include "generic.h"
>  
> -#ifdef CONFIG_PM
> -/* This function has to be defined for various drivers that are using it */
> -int at91_suspend_entering_slow_clock(void)
> -{
> -	return 0;
> -}
> -EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
> -#endif
> -
>  static const char *const samv7_dt_board_compat[] __initconst = {
>  	"atmel,samv7",
>  	NULL
> diff --git a/include/linux/platform_data/atmel.h b/include/linux/platform_data/atmel.h
> index 3c8825b67298..7b6dce7d6d33 100644
> --- a/include/linux/platform_data/atmel.h
> +++ b/include/linux/platform_data/atmel.h
> @@ -52,6 +52,13 @@ struct atmel_uart_data {
>  };
>  
>  /* FIXME: this needs a better location, but gets stuff building again */
> +#ifdef CONFIG_ATMEL_PM
>  extern int at91_suspend_entering_slow_clock(void);
> +#else
> +static inline int at91_suspend_entering_slow_clock(void)
> +{
> +	return 0;
> +}
> +#endif
>  
>  #endif /* __ATMEL_H__ */
> -- 
> 2.9.0
> 

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com