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Message-ID: <20160204082649.0ad08a16@recife.lan>
Date: Thu, 4 Feb 2016 08:26:49 -0200
From: Mauro Carvalho Chehab <mchehab@....samsung.com>
To: Shuah Khan <shuahkh@....samsung.com>
Cc: tiwai@...e.com, clemens@...isch.de, hans.verkuil@...co.com,
laurent.pinchart@...asonboard.com, sakari.ailus@...ux.intel.com,
javier@....samsung.com, pawel@...iak.com, m.szyprowski@...sung.com,
kyungmin.park@...sung.com, perex@...ex.cz, arnd@...db.de,
dan.carpenter@...cle.com, tvboxspy@...il.com, crope@....fi,
ruchandani.tina@...il.com, corbet@....net, chehabrafael@...il.com,
k.kozlowski@...sung.com, stefanr@...6.in-berlin.de,
inki.dae@...sung.com, jh1009.sung@...sung.com,
elfring@...rs.sourceforge.net, prabhakar.csengg@...il.com,
sw0312.kim@...sung.com, p.zabel@...gutronix.de,
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linux-api@...r.kernel.org, alsa-devel@...a-project.org
Subject: Re: [PATCH v2 20/22] media: au0828 add enable, disable source
handlers
Em Wed, 03 Feb 2016 21:03:52 -0700
Shuah Khan <shuahkh@....samsung.com> escreveu:
> Add enable_source and disable_source handlers.
> The enable source handler is called from
> v4l2-core, dvb-core, and ALSA drivers to check
> if the shared media source is free. The disable
> source handler is called to release the shared
> media source.
>
> Signed-off-by: Shuah Khan <shuahkh@....samsung.com>
> ---
> drivers/media/usb/au0828/au0828-core.c | 149 +++++++++++++++++++++++++++++++++
> drivers/media/usb/au0828/au0828.h | 3 +
> 2 files changed, 152 insertions(+)
>
> diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
> index 4c90f28..fd2265c 100644
> --- a/drivers/media/usb/au0828/au0828-core.c
> +++ b/drivers/media/usb/au0828/au0828-core.c
> @@ -282,6 +282,7 @@ static int au0828_create_media_graph(struct au0828_dev *dev)
> return -EINVAL;
>
> if (tuner) {
> + dev->tuner = tuner;
> /* create tuner to decoder link in deactivated state */
> ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
> decoder, 0, 0);
> @@ -373,6 +374,150 @@ void au0828_media_graph_notify(struct media_entity *new, void *notify_data)
> #endif
> }
>
> +static int au0828_enable_source(struct media_entity *entity,
> + struct media_pipeline *pipe)
> +{
> +#ifdef CONFIG_MEDIA_CONTROLLER
> + struct media_entity *source;
> + struct media_entity *sink;
> + struct media_link *link, *found_link = NULL;
> + int ret = 0;
> + struct media_device *mdev = entity->graph_obj.mdev;
> + struct au0828_dev *dev;
> +
> + if (!mdev)
> + return -ENODEV;
> +
> + /* for Audio and Video entities, source is the decoder */
> + mutex_lock(&mdev->graph_mutex);
> +
> + dev = mdev->source_priv;
> + if (!dev->tuner || !dev->decoder) {
> + ret = -ENODEV;
> + goto end;
> + }
This is wrong. There are devices without tuner (capture devices) and
without analog decoder (pure DVB devices).
In the case of pure DVB devices (e. g. no dev->decoder), it should
just enable the DVB path.
In the case of devices without tuner, it should use the same logic
needed to handle the S-Video/Composite connector inputs.
Btw, I'm not seeing how this logic would do the right thing if the user
selects either S-Video or Composite connectors.
> +
> + /*
> + * For Audio and V4L2 entity, find the link to which decoder
> + * is the sink. Look for an active link between decoder and
> + * tuner, if one exists, nothing to do. If not, look for any
> + * active links between tuner and any other entity. If one
> + * exists, tuner is busy. If tuner is free, setup link and
> + * start pipeline from source (tuner).
> + * For DVB FE entity, the source for the link is the tuner.
> + * Check if tuner is available and setup link and start
> + * pipeline.
> + */
> + if (entity->function != MEDIA_ENT_F_DTV_DEMOD)
> + sink = dev->decoder;
> + else
> + sink = entity;
> +
> + /* Is an active link between sink and tuner */
> + if (dev->active_link) {
> + if (dev->active_link->sink->entity == sink &&
> + dev->active_link->source->entity == dev->tuner) {
> + ret = 0;
> + goto end;
> + } else {
> + ret = -EBUSY;
> + goto end;
> + }
> + }
> +
> + list_for_each_entry(link, &sink->links, list) {
> + /* Check sink, and source */
> + if (link->sink->entity == sink &&
> + link->source->entity == dev->tuner) {
> + found_link = link;
> + break;
> + }
> + }
> +
> + if (!found_link) {
> + ret = -ENODEV;
> + goto end;
> + }
> +
> + /* activate link between source and sink and start pipeline */
> + source = found_link->source->entity;
> + ret = __media_entity_setup_link(found_link, MEDIA_LNK_FL_ENABLED);
> + if (ret) {
> + pr_err(
> + "Activate tuner link %s->%s. Error %d\n",
> + source->name, sink->name, ret);
> + goto end;
> + }
> +
> + ret = __media_entity_pipeline_start(entity, pipe);
> + if (ret) {
> + pr_err("Start Pipeline: %s->%s Error %d\n",
> + source->name, entity->name, ret);
> + ret = __media_entity_setup_link(found_link, 0);
> + pr_err("Deactive link Error %d\n", ret);
> + goto end;
> + }
Hmm... isn't it to early to activate the pipeline here? My original
guess is that, on the analog side, this should happen only at the stream
on code. Wouldn't this break apps like mythTV?
> + /*
> + * save active link and active link owner to avoid audio
> + * deactivating video owned link from disable_source and
> + * vice versa
> + */
> + dev->active_link = found_link;
> + dev->active_link_owner = entity;
> +end:
> + mutex_unlock(&mdev->graph_mutex);
> + pr_debug("au0828_enable_source() end %s %d %d\n",
> + entity->name, entity->function, ret);
> + return ret;
> +#endif
> + return 0;
> +}
> +
> +static void au0828_disable_source(struct media_entity *entity)
> +{
> +#ifdef CONFIG_MEDIA_CONTROLLER
> + struct media_entity *sink;
> + int ret = 0;
> + struct media_device *mdev = entity->graph_obj.mdev;
> + struct au0828_dev *dev;
> +
> + if (!mdev)
> + return;
> +
> + mutex_lock(&mdev->graph_mutex);
> + dev = mdev->source_priv;
> + if (!dev->tuner || !dev->decoder || !dev->active_link) {
> + ret = -ENODEV;
> + goto end;
> + }
Same note as before.
> +
> + if (entity->function != MEDIA_ENT_F_DTV_DEMOD)
> + sink = dev->decoder;
> + else
> + sink = entity;
> +
> + /* link is active - stop pipeline from source (tuner) */
> + if (dev->active_link && dev->active_link->sink->entity == sink &&
> + dev->active_link->source->entity == dev->tuner) {
> + /*
> + * prevent video from deactivating link when audio
> + * has active pipeline
> + */
> + if (dev->active_link_owner != entity)
> + goto end;
> + __media_entity_pipeline_stop(entity);
> + ret = __media_entity_setup_link(dev->active_link, 0);
> + if (ret)
> + pr_err("Deactive link Error %d\n", ret);
> + dev->active_link = NULL;
> + dev->active_link_owner = NULL;
> + }
Most code here looks like the one at au0828_enable_source(). Wouldn't
be simpler to merge those code and add a "bool enable" to the function
parameters?
> +
> +end:
> + mutex_unlock(&mdev->graph_mutex);
> +#endif
> +}
> +
> static int au0828_media_device_register(struct au0828_dev *dev,
> struct usb_device *udev)
> {
> @@ -403,6 +548,10 @@ static int au0828_media_device_register(struct au0828_dev *dev,
> ret);
> return ret;
> }
> + /* set enable_source */
> + dev->media_dev->source_priv = (void *) dev;
> + dev->media_dev->enable_source = au0828_enable_source;
> + dev->media_dev->disable_source = au0828_disable_source;
> #endif
> return 0;
> }
> diff --git a/drivers/media/usb/au0828/au0828.h b/drivers/media/usb/au0828/au0828.h
> index 54379ec..a7c88a1 100644
> --- a/drivers/media/usb/au0828/au0828.h
> +++ b/drivers/media/usb/au0828/au0828.h
> @@ -284,6 +284,9 @@ struct au0828_dev {
> struct media_entity input_ent[AU0828_MAX_INPUT];
> struct media_pad input_pad[AU0828_MAX_INPUT];
> struct media_entity_notify entity_notify;
> + struct media_entity *tuner;
> + struct media_link *active_link;
> + struct media_entity *active_link_owner;
> #endif
> };
>
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