[RFC PATCH] drm/print: Add deprecation notes to DRM_...() functions

[Doug Anderson]

Hi,

On Tue, Sep 21, 2021 at 8:28 AM Douglas Anderson <dianders at chromium.org> wrote:
>
> It's hard for someone (like me) who's not following closely to know
> what the suggested best practices are for error printing in DRM
> drivers. Add some hints to the header file.
>
> In general, my understanding is that:
> * When possible we should be using a `struct drm_device` for logging
>   and recent patches have tried to make it more possible to access a
>   relevant `struct drm_device` in more places.
> * For most cases when we don't have a `struct drm_device`, we no
>   longer bother with DRM-specific wrappers on the dev_...() functions
>   or pr_...() functions and just encourage drivers to use the normal
>   functions.
> * For debug-level functions where we might want filtering based on a
>   category we'll still have DRM-specific wrappers, but we'll only
>   support passing a `struct drm_device`, not a `struct
>   device`. Presumably most of the cases where we want the filtering
>   are messages that happen while the system is in a normal running
>   state (AKA not during probe time) and we should have a `struct
>   drm_device` then. If we absolutely can't get a `struct drm_device`
>   then these functions begrudgingly accept NULL for the `struct
>   drm_device` and hopefully the awkwardness of having to manually pass
>   NULL will keep people from doing this unless absolutely necessary.
>
> Signed-off-by: Douglas Anderson <dianders at chromium.org>
> ---
>
>  include/drm/drm_print.h | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)

Landed in drm-misc-next:

306589856399 drm/print: Add deprecation notes to DRM_...() functions