Re: [PATCH] dmaengine: edma: fix build without CONFIG_OF

[Peter Ujfalusi <peter.ujfalusi@ti.com>]

On 11/03/2015 04:00 PM, Arnd Bergmann wrote:
> During the edma rework, a build error was introduced for the
> case that CONFIG_OF is disabled:
> 
> drivers/built-in.o: In function `edma_tc_set_pm_state':
> :(.text+0x43bf0): undefined reference to `of_find_device_by_node'
> 
> As the edma_tc_set_pm_state() function does nothing in case
> we are running without OF, this adds an IS_ENABLED() check
> that turns the function into an empty stub then and avoids the
> link error.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: ca304fa9bb76 ("ARM/dmaengine: edma: Public API to use private struct pointer")

The actual commit this patch is fixing is:
1be5336bc7ba dmaengine: edma: New device tree binding

> ---
> Found on ARM randconfig builds with today's linux-next

I have sanity built the kernel with omap2plus_defconfig and
davinci_all_defconfig since eDMA is used by these platforms and did not faced
with this issue, as obviously these defconfigs will result OF to be enabled.

> diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
> index 31722d436a42..16713a93da10 100644
> --- a/drivers/dma/edma.c
> +++ b/drivers/dma/edma.c
> @@ -1560,7 +1560,7 @@ static void edma_tc_set_pm_state(struct edma_tc *tc, bool enable)
>  	struct platform_device *tc_pdev;
>  	int ret;
>  
> -	if (!tc)
> +	if (!IS_ENABLED(CONFIG_OF) || !tc)
>  		return;

Should we instead put the function inside of:
#if IS_ENABLED(CONFIG_OF)
static void edma_tc_set_pm_state(struct edma_tc *tc, bool enable)
{
...
}
#else
static inline void edma_tc_set_pm_state(struct edma_tc *tc, bool enable)
{
}
#endif /* IS_ENABLED(CONFIG_OF) */


>  
>  	tc_pdev = of_find_device_by_node(tc->node);
> 

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