Re: [PATCH v2 10/11] OMAP: DMA: Use DMA device attributes

[Kevin Hilman <khilman@deeprootsystems.com>]

Manjunatha GK <manjugk@ti.com> writes:

> Existing DMA API's are using cpu_is_xxxx checks for differenciating
> omap1 and omap2plus code.
>
> This patch replaces cpu_is_xxxx checks with DMA device attributes and
> also moves API's which are OMAP1 and OMAP2plus specific into respective
> mach-omap dma driver files.
>
> Signed-off-by: Manjunatha GK <manjugk@ti.com>
> Cc: Benoit Cousson <b-cousson@ti.com>
> Cc: Kevin Hilman <khilman@deeprootsystems.com>
> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>

[...]

>  int omap_request_dma(int dev_id, const char *dev_name,
>  		     void (*callback)(int lch, u16 ch_status, void *data),
>  		     void *data, int *dma_ch_out)
> @@ -754,14 +459,12 @@ int omap_request_dma(int dev_id, const char *dev_name,
>  	chan = dma_chan + free_ch;
>  	chan->dev_id = dev_id;
>  
> -	pm_runtime_get_sync(&ddev->dev);
> -
> -	if (cpu_class_is_omap1())
> -		clear_lch_regs(free_ch);
> -
> -	if (cpu_class_is_omap2())
> +	if (p->clear_lch_regs)
> +		p->clear_lch_regs(free_ch);
> +	else
>  		omap_clear_dma(free_ch);

You access HW registers here.

> +	pm_runtime_get_sync(&ddev->dev);

But don't actually enable HW until here.  

IOW, you need to have the 'get' before you access the HW.

Kevin