[PATCH v2 1/2] drm: add drmm_encoder_init()

Daniel Vetter daniel at ffwll.ch
Fri Jul 24 09:40:09 UTC 2020


On Fri, Jul 24, 2020 at 11:37 AM Daniel Vetter <daniel at ffwll.ch> wrote:
>
> On Fri, Jul 24, 2020 at 11:33 AM Thomas Zimmermann <tzimmermann at suse.de> wrote:
> >
> > Hi
> >
> > Am 24.07.20 um 11:07 schrieb Daniel Vetter:
> > > On Fri, Jul 24, 2020 at 10:49 AM Philipp Zabel <p.zabel at pengutronix.de> wrote:
> > >>
> > >> On Thu, 2020-07-23 at 16:56 +0200, Philipp Zabel wrote:
> > >>> Add a drm_encoder_init() variant that allocates an encoder with
> > >>> drmm_kzalloc() and registers drm_encoder_cleanup() with
> > >>> drmm_add_action_or_reset().
> > >>>
> > >>> Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
> > >
> > > Thanks for doing this!
> > >
> > >>> ---
> > >>> New in v2
> > >>> ---
> > >>>  drivers/gpu/drm/drm_encoder.c | 101 ++++++++++++++++++++++++++--------
> > >>>  include/drm/drm_encoder.h     |  30 ++++++++++
> > >>>  2 files changed, 108 insertions(+), 23 deletions(-)
> > >>>
> > >>> diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
> > >>> index e555281f43d4..91184f67333c 100644
> > >>> --- a/drivers/gpu/drm/drm_encoder.c
> > >>> +++ b/drivers/gpu/drm/drm_encoder.c
> > >>> @@ -26,6 +26,7 @@
> > >>>  #include <drm/drm_device.h>
> > >>>  #include <drm/drm_drv.h>
> > >>>  #include <drm/drm_encoder.h>
> > >>> +#include <drm/drm_managed.h>
> > >>>
> > >>>  #include "drm_crtc_internal.h"
> > >>>
> > >>> @@ -91,25 +92,10 @@ void drm_encoder_unregister_all(struct drm_device *dev)
> > >>>       }
> > >>>  }
> > >>>
> > >>> -/**
> > >>> - * drm_encoder_init - Init a preallocated encoder
> > >>> - * @dev: drm device
> > >>> - * @encoder: the encoder to init
> > >>> - * @funcs: callbacks for this encoder
> > >>> - * @encoder_type: user visible type of the encoder
> > >>> - * @name: printf style format string for the encoder name, or NULL for default name
> > >>> - *
> > >>> - * Initialises a preallocated encoder. Encoder should be subclassed as part of
> > >>> - * driver encoder objects. At driver unload time drm_encoder_cleanup() should be
> > >>> - * called from the driver's &drm_encoder_funcs.destroy hook.
> > >>> - *
> > >>> - * Returns:
> > >>> - * Zero on success, error code on failure.
> > >>> - */
> > >>> -int drm_encoder_init(struct drm_device *dev,
> > >>> -                  struct drm_encoder *encoder,
> > >>> -                  const struct drm_encoder_funcs *funcs,
> > >>> -                  int encoder_type, const char *name, ...)
> > >>> +static int __drm_encoder_init(struct drm_device *dev,
> > >>> +                           struct drm_encoder *encoder,
> > >>> +                           const struct drm_encoder_funcs *funcs,
> > >>> +                           int encoder_type, const char *name, va_list ap)
> > >>>  {
> > >>>       int ret;
> > >>>
> > >>> @@ -125,11 +111,7 @@ int drm_encoder_init(struct drm_device *dev,
> > >>>       encoder->encoder_type = encoder_type;
> > >>>       encoder->funcs = funcs;
> > >>>       if (name) {
> > >>> -             va_list ap;
> > >>> -
> > >>> -             va_start(ap, name);
> > >>>               encoder->name = kvasprintf(GFP_KERNEL, name, ap);
> > >>> -             va_end(ap);
> > >>>       } else {
> > >>>               encoder->name = kasprintf(GFP_KERNEL, "%s-%d",
> > >>>                                         drm_encoder_enum_list[encoder_type].name,
> > >>> @@ -150,6 +132,38 @@ int drm_encoder_init(struct drm_device *dev,
> > >>>
> > >>>       return ret;
> > >>>  }
> > >>> +
> > >>> +/**
> > >>> + * drm_encoder_init - Init a preallocated encoder
> > >>> + * @dev: drm device
> > >>> + * @encoder: the encoder to init
> > >>> + * @funcs: callbacks for this encoder
> > >>> + * @encoder_type: user visible type of the encoder
> > >>> + * @name: printf style format string for the encoder name, or NULL for default name
> > >>> + *
> > >>> + * Initialises a preallocated encoder. Encoder should be subclassed as part of
> > >>> + * driver encoder objects. At driver unload time drm_encoder_cleanup() should be
> > >>> + * called from the driver's &drm_encoder_funcs.destroy hook.
> > >>> + *
> > >>> + * Returns:
> > >>> + * Zero on success, error code on failure.
> > >>> + */
> > >>> +int drm_encoder_init(struct drm_device *dev,
> > >>> +                  struct drm_encoder *encoder,
> > >>> +                  const struct drm_encoder_funcs *funcs,
> > >>> +                  int encoder_type, const char *name, ...)
> > >>> +{
> > >>> +     va_list ap;
> > >>> +     int ret;
> > >>> +
> > >>> +     if (name)
> > >>> +             va_start(ap, name);
> > >>> +     ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
> > >>> +     if (name)
> > >>> +             va_end(ap);
> > >>> +
> > >>> +     return ret;
> > >>> +}
> > >>>  EXPORT_SYMBOL(drm_encoder_init);
> > >>>
> > >>>  /**
> > >>> @@ -181,6 +195,47 @@ void drm_encoder_cleanup(struct drm_encoder *encoder)
> > >>>  }
> > >>>  EXPORT_SYMBOL(drm_encoder_cleanup);
> > >>>
> > >>> +void drmm_encoder_init_release(struct drm_device *dev, void *ptr)
> > >>> +{
> > >>> +     struct drm_encoder *encoder = ptr;
> > >>
> > >> I'll add
> > >>
> > >>         if (WARN_ON(!encoder->dev))
> > >>                 return;
> > >>
> > >> here.
> > >>
> > >>> +     drm_encoder_cleanup(encoder);
> > >>> +}
> > >>> +
> > >>> +void *__drmm_encoder_init(struct drm_device *dev, size_t size, size_t offset,
> > >>> +                       const struct drm_encoder_funcs *funcs,
> > >>> +                       int encoder_type, const char *name, ...)
> > >>> +{
> > >>> +     void *container;
> > >>> +     struct drm_encoder *encoder;
> > >>> +     va_list ap;
> > >>> +     int ret;
> > >>> +
> > >>> +     if (WARN_ON(!funcs || funcs->destroy))
> > >>> +             return ERR_PTR(-EINVAL);
> > >>> +
> > >>> +     container = drmm_kzalloc(dev, size, GFP_KERNEL);
> > >>> +     if (!container)
> > >>> +             return ERR_PTR(-EINVAL);
> > >>> +
> > >>> +     encoder = container + offset;
> > >>> +
> > >>> +     if (name)
> > >>> +             va_start(ap, name);
> > >>> +     ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
> > >>> +     if (name)
> > >>> +             va_end(ap);
> > >>> +     if (ret)
> > >>> +             return ERR_PTR(ret);
> > >>> +
> > >>> +     ret = drmm_add_action_or_reset(dev, drmm_encoder_init_release, encoder);
> > >>> +     if (ret)
> > >>> +             return ERR_PTR(ret);
> > >>> +
> > >>> +     return container;
> > >>> +}
> > >>> +EXPORT_SYMBOL(__drmm_encoder_init);
> > >>> +
> > >>>  static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder)
> > >>>  {
> > >>>       struct drm_connector *connector;
> > >>> diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h
> > >>> index a60f5f1555ac..54b82554ee88 100644
> > >>> --- a/include/drm/drm_encoder.h
> > >>> +++ b/include/drm/drm_encoder.h
> > >>> @@ -195,6 +195,36 @@ int drm_encoder_init(struct drm_device *dev,
> > >>>                    const struct drm_encoder_funcs *funcs,
> > >>>                    int encoder_type, const char *name, ...);
> > >>>
> > >>> +__printf(6, 7)
> > >>> +void *__drmm_encoder_init(struct drm_device *dev,
> > >>> +                       size_t size, size_t offset,
> > >>> +                       const struct drm_encoder_funcs *funcs,
> > >>> +                       int encoder_type,
> > >>> +                       const char *name, ...);
> > >>> +
> > >>> +/**
> > >>> + * drmm_encoder_init - Allocate and initialize an encoder
> > >>> + * @dev: drm device
> > >>> + * @type: the type of the struct which contains struct &drm_encoder
> > >>> + * @member: the name of the &drm_encoder within @type.
> > >>> + * @funcs: callbacks for this encoder
> > >>> + * @encoder_type: user visible type of the encoder
> > >>> + * @name: printf style format string for the encoder name, or NULL for default name
> > >>> + *
> > >>> + * Allocates and initializes an encoder. Encoder should be subclassed as part of
> > >>> + * driver encoder objects. Cleanup is automatically handled through registering
> > >>> + * drm_encoder_cleanup() with drmm_add_action().
> > >>> + *
> > >>> + * The @drm_encoder_funcs.destroy hook must be NULL.
> > >>> + *
> > >>> + * Returns:
> > >>> + * Pointer to new encoder, or ERR_PTR on failure.
> > >>> + */
> > >>> +#define drmm_encoder_init(dev, type, member, funcs, encoder_type, name, ...) \
> > >>> +     ((type *) __drmm_encoder_init(dev, sizeof(type), \
> > >>> +                                   offsetof(type, member), funcs, \
> > >>> +                                   encoder_type, name, ##__VA_ARGS__))
> > >>> +
> > >>
> > >> Should this be called drmm_encoder_alloc instead?
> > >
> > > Yes. Same for the internal helper for consistency. Also see my other
> >
> > I'd suggest calling it drmm_encoder_create() to express that it's _alloc
> > + _init. Calling it just _alloc sounds as if it doesn't do the _init.
>
> At least in drm the pattern we've had thus far is alloc = kzalloc +
> init. We do use create, but that's for properties and files and stuff,
> not allocating/initing driver objects.
>
> So maybe a bit a bikeshed, but imo alloc() is more consistent with
> e.g. devm_drm_dev_alloc. Otherwise I think we should rename that one
> (and all related ones) for consistency.

_create also sounds a bit too much like "completely create" to me,
this _alloc here is very much just a small part of what it takes to
create a complete encoder. The create functions we do have are a lot
more the kind of "it's all done, including all the links and
registering and everything".
-Daniel

> -Daniel
>
> >
> > Best regards
> > Thomas
> >
> > > reply, if the _alloc() variant is all that's needed that makes me
> > > happy, since then we don't need to code up the drmm_assert_managed
> > > check for the _init() variants to make sure drivers dont give it
> > > something stupid like a devm_kzalloc range :-)
> > > -Daniel
> > >
> >
> > --
> > Thomas Zimmermann
> > Graphics Driver Developer
> > SUSE Software Solutions Germany GmbH
> > Maxfeldstr. 5, 90409 Nürnberg, Germany
> > (HRB 36809, AG Nürnberg)
> > Geschäftsführer: Felix Imendörffer
> >
>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch



-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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