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

From: Doug Anderson
Date: Fri Sep 24 2021 - 17:59:34 EST


On Tue, Sep 21, 2021 at 8:28 AM Douglas Anderson <dianders@xxxxxxxxxxxx> 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@xxxxxxxxxxxx>
> ---
> 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