Re: [PATCH 2/3] components: multiple components for a device

Daniel Vetter
2019-02-07T22:40:24Z

On Wed, Feb 06, 2019 at 11:57:04PM +0100, Rafael J. Wysocki wrote:
> ) On Wed, Feb 6, 2019 at 5:46 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> >
> > Component framework is extended to support multiple components for
> > a struct device. These will be matched with different masters based on
> > its sub component value.
> >
> > We are introducing this, as I915 needs two different components
> > with different subcomponent value, which will be matched to two
> > different component masters(Audio and HDCP) based on the subcomponent
> > values.
> >
> > v2: Add documenation.
> >
> > v3: Rebase on top of updated documenation.
> >
> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1 code)
> > Signed-off-by: Ramalingam C <ramalingam.c@intel.com> (v1 commit message)
> > Cc: Ramalingam C <ramalingam.c@intel.com>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Russell King <rmk+kernel@arm.linux.org.uk>
> > Cc: Rafael J. Wysocki <rafael@kernel.org>
> > Cc: Jaroslav Kysela <perex@perex.cz>
> > Cc: Takashi Iwai <tiwai@suse.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > Cc: Jani Nikula <jani.nikula@linux.intel.com>
> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > ---
> > drivers/base/component.c | 160 +++++++++++++++++++++++++++++---------
> > include/linux/component.h | 9 ++-
> > 2 files changed, 129 insertions(+), 40 deletions(-)
> >
> > diff --git a/drivers/base/component.c b/drivers/base/component.c
> > index f34d4b784709..68ccd5a0d5d6 100644
> > --- a/drivers/base/component.c
> > +++ b/drivers/base/component.c
> > @@ -47,6 +47,7 @@ struct component;
> > struct component_match_array {
> > void *data;
> > int (*compare)(struct device *, void *);
> > + int (*compare_typed)(struct device *, int, void *);
> > void (*release)(struct device *, void *);
> > struct component *component;
> > bool duplicate;
> > @@ -74,6 +75,7 @@ struct component {
> > bool bound;
> >
> > const struct component_ops *ops;
> > + int subcomponent;
> > struct device *dev;
> > };
> >
> > @@ -158,7 +160,7 @@ static struct master *__master_find(struct device *dev,
> > }
> >
> > static struct component *find_component(struct master *master,
> > - int (*compare)(struct device *, void *), void *compare_data)
> > + struct component_match_array *mc)
> > {
> > struct component *c;
> >
> > @@ -166,8 +168,13 @@ static struct component *find_component(struct master *master,
> > if (c->master && c->master != master)
> > continue;
> >
> > - if (compare(c->dev, compare_data))
> > + if (mc->compare_typed) {
> > + if (mc->compare_typed(c->dev, c->subcomponent,
> > + mc->data))
>
> This line break looks kind of weird to me,
>
> > + return c;
> > + } else if (mc->compare(c->dev, mc->data)) {
> > return c;
> > + }
>
> Also, why don't you do
>
> if (mc->compare(c->dev, mc->data) || (mc->compare_typed &&
> mc->compare_typed(c->dev, c->subcomponent, mc->data)))
> return c;
>
> The only difference is that ->compare() will run first and if it finds
> a match, c will be returned right away. Does it matter?

Tried it, yes it does matter: We have either ->compare or ->compare_typed,
so calling one unconditionally blows up. Can still be streamlined a bit I
think.
-Daniel

>
> > }
> >
> > return NULL;
> > @@ -192,7 +199,7 @@ static int find_components(struct master *master)
> > if (match->compare[i].component)
> > continue;
> >
> > - c = find_component(master, mc->compare, mc->data);
> > + c = find_component(master, mc);
> > if (!c) {
> > ret = -ENXIO;
> > break;
> > @@ -327,30 +334,12 @@ static int component_match_realloc(struct device *dev,
> > return 0;
> > }
> >
> > -/**
> > - * component_match_add_release - add a component match with release callback
> > - * @master: device with the aggregate driver
> > - * @matchptr: pointer to the list of component matches
> > - * @release: release function for @compare_data
> > - * @compare: compare function to match against all components
> > - * @compare_data: opaque pointer passed to the @compare function
> > - *
> > - * This adds a new component match to the list stored in @matchptr, which the
>
> "This" appears to be redundant here (and in some places below too).

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org