Re: [PATCH] arm: mach-omap2: pm: cleanup !CONFIG_SUSPEND handling

[Kevin Hilman <khilman@ti.com>]

Hi Aaro,

Aaro Koskinen <aaro.koskinen@nokia.com> writes:

> Make !CONFIG_SUSPEND init declarations identical on all OMAPs and
> eliminate some ifdefs.
>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>

I like this solution, but it introduces compiler warnings:

/opt/home/khilman/work.local/kernel/omap/pm/arch/arm/mach-omap2/pm44xx.c: In function 'omap4_pm_init':
/opt/home/khilman/work.local/kernel/omap/pm/arch/arm/mach-omap2/pm44xx.c:119: warning: passing argument 1 of 'suspend_set_ops' discards qualifiers from pointer target type
/opt/home/khilman/work.local/kernel/omap/pm/include/linux/suspend.h:125: note: expected 'struct platform_suspend_ops *' but argument is of type 'const struct platform_suspend_ops *'
/opt/home/khilman/work.local/kernel/omap/pm/arch/arm/mach-omap2/pm24xx.c: In function 'omap2_pm_init':
/opt/home/khilman/work.local/kernel/omap/pm/arch/arm/mach-omap2/pm24xx.c:585: warning: passing argument 1 of 'suspend_set_ops' discards qualifiers from pointer target type
/opt/home/khilman/work.local/kernel/omap/pm/include/linux/suspend.h:125: note: expected 'struct platform_suspend_ops *' but argument is of type 'const struct platform_suspend_ops *'
/opt/home/khilman/work.local/kernel/omap/pm/arch/arm/mach-omap2/pm34xx.c: In function 'omap3_pm_init':
/opt/home/khilman/work.local/kernel/omap/pm/arch/arm/mach-omap2/pm34xx.c:1072: warning: passing argument 1 of 'suspend_set_ops' discards qualifiers from pointer target type
/opt/home/khilman/work.local/kernel/omap/pm/include/linux/suspend.h:125:
note: expected 'struct platform_suspend_ops *' but argument is of type
'const struct platform_suspend_ops *'

As you likely noticed, removing the const leads to checkpatch warnings:

WARNING: struct platform_suspend_ops should normally be const

so the choice is between a checkpatch warning or a bunch of compiler
warnings.

Alternatively, I just posted a patch[1] to linux-pm propsing to fix this
at the source.  Let's see what happens there.  Merging $SUBJECT patch
will depend on how this is fixed upstream.

Kevin

[1] https://patchwork.kernel.org/patch/455831/

> ---
>  arch/arm/mach-omap2/pm.h     |    4 ++++
>  arch/arm/mach-omap2/pm24xx.c |   16 ++++++++--------
>  arch/arm/mach-omap2/pm34xx.c |   16 ++++++++--------
>  arch/arm/mach-omap2/pm44xx.c |   17 +++++++++--------
>  4 files changed, 29 insertions(+), 24 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
> index 1c1b0ab..704766b 100644
> --- a/arch/arm/mach-omap2/pm.h
> +++ b/arch/arm/mach-omap2/pm.h
> @@ -138,4 +138,8 @@ static inline int omap4_twl_init(void)
>  }
>  #endif
>  
> +#ifndef CONFIG_SUSPEND
> +#define omap_pm_ops NULL
> +#endif
> +
>  #endif
> diff --git a/arch/arm/mach-omap2/pm24xx.c b/arch/arm/mach-omap2/pm24xx.c
> index dac2d1d..e65b329 100644
> --- a/arch/arm/mach-omap2/pm24xx.c
> +++ b/arch/arm/mach-omap2/pm24xx.c
> @@ -350,14 +350,14 @@ static void omap2_pm_end(void)
>  	enable_hlt();
>  }
>  
> -static struct platform_suspend_ops omap_pm_ops = {
> -	.begin		= omap2_pm_begin,
> -	.enter		= omap2_pm_enter,
> -	.end		= omap2_pm_end,
> -	.valid		= suspend_valid_only_mem,
> +static const struct platform_suspend_ops omap_pm_ops[] = {
> +	{
> +		.begin		= omap2_pm_begin,
> +		.enter		= omap2_pm_enter,
> +		.end		= omap2_pm_end,
> +		.valid		= suspend_valid_only_mem,
> +	}
>  };
> -#else
> -static const struct platform_suspend_ops __initdata omap_pm_ops;
>  #endif /* CONFIG_SUSPEND */
>  
>  /* XXX This function should be shareable between OMAP2xxx and OMAP3 */
> @@ -582,7 +582,7 @@ static int __init omap2_pm_init(void)
>  						    omap24xx_cpu_suspend_sz);
>  	}
>  
> -	suspend_set_ops(&omap_pm_ops);
> +	suspend_set_ops(omap_pm_ops);
>  	pm_idle = omap2_pm_idle;
>  
>  	return 0;
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index 5b323f2..a4c9283 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -605,11 +605,13 @@ static void omap3_pm_end(void)
>  	return;
>  }
>  
> -static struct platform_suspend_ops omap_pm_ops = {
> -	.begin		= omap3_pm_begin,
> -	.end		= omap3_pm_end,
> -	.enter		= omap3_pm_enter,
> -	.valid		= suspend_valid_only_mem,
> +static const struct platform_suspend_ops omap_pm_ops[] = {
> +	{
> +		.begin		= omap3_pm_begin,
> +		.end		= omap3_pm_end,
> +		.enter		= omap3_pm_enter,
> +		.valid		= suspend_valid_only_mem,
> +	}
>  };
>  #endif /* CONFIG_SUSPEND */
>  
> @@ -1067,9 +1069,7 @@ static int __init omap3_pm_init(void)
>  	core_clkdm = clkdm_lookup("core_clkdm");
>  
>  	omap_push_sram_idle();
> -#ifdef CONFIG_SUSPEND
> -	suspend_set_ops(&omap_pm_ops);
> -#endif /* CONFIG_SUSPEND */
> +	suspend_set_ops(omap_pm_ops);
>  
>  	pm_idle = omap3_pm_idle;
>  	omap3_idle_init();
> diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
> index e9f4862..6022c0a 100644
> --- a/arch/arm/mach-omap2/pm44xx.c
> +++ b/arch/arm/mach-omap2/pm44xx.c
> @@ -16,6 +16,7 @@
>  #include <linux/err.h>
>  #include <linux/slab.h>
>  
> +#include "pm.h"
>  #include "powerdomain.h"
>  #include <mach/omap4-common.h>
>  
> @@ -65,11 +66,13 @@ static void omap4_pm_end(void)
>  	return;
>  }
>  
> -static struct platform_suspend_ops omap_pm_ops = {
> -	.begin		= omap4_pm_begin,
> -	.end		= omap4_pm_end,
> -	.enter		= omap4_pm_enter,
> -	.valid		= suspend_valid_only_mem,
> +static const struct platform_suspend_ops omap_pm_ops[] = {
> +	{
> +		.begin		= omap4_pm_begin,
> +		.end		= omap4_pm_end,
> +		.enter		= omap4_pm_enter,
> +		.valid		= suspend_valid_only_mem,
> +	}
>  };
>  #endif /* CONFIG_SUSPEND */
>  
> @@ -113,9 +116,7 @@ static int __init omap4_pm_init(void)
>  	}
>  #endif
>  
> -#ifdef CONFIG_SUSPEND
> -	suspend_set_ops(&omap_pm_ops);
> -#endif /* CONFIG_SUSPEND */
> +	suspend_set_ops(omap_pm_ops);
>  
>  err2:
>  	return ret;