[PATCH RESEND] drm/mediatek: Add valid modifier check

[AngeloGioacchino Del Regno]

Il 26/07/23 21:44, Justin Green ha scritto:
>> Would it make more sense to commmonize function mtk_plane_format_mod_supported()
>> and call that one here instead?
> I had considered that, but mtk_plane_format_mod_supported() is
> required to take a drm_plane as a parameter in order to conform to the
> type signature defined in drm_plane_funcs, but
> mtk_drm_mode_fb_create() does not have a drm_plane to provide, since
> the framebuffer is created later in the function. Technically we don't
> actually use the drm_plane in the implementation of
> mtk_plane_format_mod_supported() today, so we could just use a null
> pointer, but I figured we may one day need to add per-plane logic.
> 

My suggestion was not to use that function as-is, but rather to add a helper like

bool mtk_format_modifier_supported(u32 format, u32 modifier) { ... }

...so that a per-plane logic in mtk_drm_plane can be easily added, because...

static bool mtk_plane_format_mod_supported(struct drm_plane *plane,
					   u32 format, u32 modifier)
{
	return mtk_format_modifier_supported(format, modifier);
}

so apart from that, is there any other reason to not do that? :-)

Regards,
Angelo

>> This is not DRM_FORMAT_MOD_INVALID. Please either explicitly compare against INVALID if that's what you meant, or against LINEAR if that's what you meant, or both.
> Ack, I meant to use LINEAR. Will update for the next version of the patch.