Re: [RFC PATCH v2 0/3] Add support modifiers for drivers whose planes only support linear layout

[Daniel Stone]

Hi Esaki-san,

On Thu, 13 Jan 2022 at 09:44, Tomohito Esaki <etom@xxxxxxxxxx> wrote:
> Some drivers whose planes only support linear layout fb do not support format
> modifiers.
> These drivers should support modifiers, however the DRM core should handle this
> rather than open-coding in every driver.
>
> In this patch series, these drivers expose format modifiers based on the
> following suggestion[1].

Thanks for the series, it looks like the right thing to do.

Can you please change the patch ordering though? At the moment there
will be a bisection break at patch #1, because the legacy drivers will
suddenly start gaining modifier support, before it is removed in patch
#2.

I think a better order would be:
  1: add fb_modifiers_not_supported flag to core and drivers
  2: add default modifiers (and set allow_fb_modifiers) if
fb_modifiers_not_supported flag is not set
  3: remove allow_fb_modifiers flag

Cheers,
Daniel