Re: [PATCH v2 2/6] staging: fbtft: do not override DMA coherent mask

[Noralf TrÃnnes]

Den 02.01.2017 12:35, skrev Andy Shevchenko:
> Usually it's not consumer's business to override resources passed from
> provider, in particularly DMA coherent mask.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
>   drivers/staging/fbtft/fbtft-core.c | 1 -
>   1 file changed, 1 deletion(-)
>
> diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
> index e8bf0d1ec11f..226be8c09768 100644
> --- a/drivers/staging/fbtft/fbtft-core.c
> +++ b/drivers/staging/fbtft/fbtft-core.c
> @@ -841,7 +841,6 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
>   	if (txbuflen > 0) {
>   #ifdef CONFIG_HAS_DMA
>   		if (dma) {
> -			dev->coherent_dma_mask = ~0;

Can we make this conditional like in of_dma_configure():

         if (!dev->coherent_dma_mask)
                dev->coherent_dma_mask = DMA_BIT_MASK(32);

If not, I guess the mask has to be set before adding the spi device in
fbtft_device.c to keep it from breaking.

Noralf.

>   			txbuf = dmam_alloc_coherent(dev, txbuflen,
>   						    &par->txbuf.dma, GFP_DMA);
>   		} else