Re: [PATCH] drm/stm: check pitch and size calculations even if !CONFIG_MMU

From: Philippe CORNU
Date: Tue Jan 30 2018 - 15:02:54 EST


Hi Benjamin,

Working on a coming patch (based on the new has_alpha field in fourcc),
I realized that in particular cases (2 layers + "odd" layer sizes)
memory transfers on MCU are greatly improved too if drm buffers are
aligned on 128 bytes : )

So I suggest to cancel this patch.

Then you can post a new one removing ifdef CONFIG_MMU endif, or I can do
it, it is up to you.

Many thanks for your support,
Philippe :-)

On 01/30/2018 04:24 PM, Benjamin Gaignard wrote:
> In all cases we have to check pitch and size calculations.
> Rely on drm_gem_cma_dumb_create for no MMU cases.
>
> Fixes: 21f815bf773c ("drm/stm: drv: Improve data transfers")
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx>
> ---
> drivers/gpu/drm/stm/drv.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
> index 8bc7e8418b8d..3e0fb5f34b8e 100644
> --- a/drivers/gpu/drm/stm/drv.c
> +++ b/drivers/gpu/drm/stm/drv.c
> @@ -44,9 +44,11 @@ static int stm_gem_cma_dumb_create(struct drm_file *file,
> */
> args->pitch = roundup(min_pitch, 128);
> args->height = roundup(args->height, 4);
> -#endif
>
> return drm_gem_cma_dumb_create_internal(file, dev, args);
> +#else
> + return drm_gem_cma_dumb_create(file, dev, args);
> +#endif
> }
>
> DEFINE_DRM_GEM_CMA_FOPS(drv_driver_fops);
>