diff mbox

[v8,3/3] drm: writeback: Add client capability for exposing writeback connectors

Message ID 20180518151743.29937-4-Liviu.Dudau@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Liviu Dudau May 18, 2018, 3:17 p.m. UTC
Due to the fact that writeback connectors behave in a special way
in DRM (they always report being disconnected) we might confuse some
userspace. Add a client capability for writeback connectors that will
filter them out for clients that don't understand the capability.

Re-requested-by: Sean Paul <seanpaul@chromium.org>
Cc: Brian Starkey <brian.starkey@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
---
 drivers/gpu/drm/drm_ioctl.c       | 7 +++++++
 drivers/gpu/drm/drm_mode_config.c | 5 +++++
 include/drm/drm_file.h            | 7 +++++++
 include/uapi/drm/drm.h            | 9 +++++++++
 4 files changed, 28 insertions(+)

Comments

Maarten Lankhorst May 23, 2018, 9:34 a.m. UTC | #1
Op 18-05-18 om 17:17 schreef Liviu Dudau:
> Due to the fact that writeback connectors behave in a special way
> in DRM (they always report being disconnected) we might confuse some
> userspace. Add a client capability for writeback connectors that will
> filter them out for clients that don't understand the capability.
>
> Re-requested-by: Sean Paul <seanpaul@chromium.org>
> Cc: Brian Starkey <brian.starkey@arm.com>
> Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
> ---
>  drivers/gpu/drm/drm_ioctl.c       | 7 +++++++
>  drivers/gpu/drm/drm_mode_config.c | 5 +++++
>  include/drm/drm_file.h            | 7 +++++++
>  include/uapi/drm/drm.h            | 9 +++++++++
>  4 files changed, 28 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index af782911c505d..59951ff3e3630 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -325,6 +325,13 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
>  		file_priv->atomic = req->value;
>  		file_priv->universal_planes = req->value;
>  		break;
> +	case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
> +		if (!file_priv->atomic || !drm_core_check_feature(dev, DRIVER_ATOMIC))
> +			return -EINVAL;
Wondering how you can set the atomic cap without DRIVER_ATOMIC. :)

That part could be dropped I think. We should probably WARN when trying to create a writeback connector without the DRIVER_ATOMIC cap set.
> +		if (req->value > 1)
> +			return -EINVAL;
> +		file_priv->writeback_connectors = req->value;
> +		break;
>  	default:
>  		return -EINVAL;
>  	}
> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> index e5c653357024d..21e353bd3948e 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -145,6 +145,11 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
>  	count = 0;
>  	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
>  	drm_for_each_connector_iter(connector, &conn_iter) {
> +		/* only expose writeback connectors if userspace understands them */
> +		if (!file_priv->writeback_connectors &&
> +		    (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))
> +			continue;
> +
>  		if (drm_lease_held(file_priv, connector->base.id)) {
>  			if (count < card_res->count_connectors &&
>  			    put_user(connector->base.id, connector_id + count)) {
> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> index 5176c3797680c..2a09b3c8965c6 100644
> --- a/include/drm/drm_file.h
> +++ b/include/drm/drm_file.h
> @@ -181,6 +181,13 @@ struct drm_file {
>  	/** @atomic: True if client understands atomic properties. */
>  	unsigned atomic:1;
>  
> +	/**
> +	 * @writeback_connectors:
> +	 *
> +	 * True if client understands writeback connectors
> +	 */
> +	unsigned writeback_connectors:1;
> +
>  	/**
>  	 * @is_master:
>  	 *
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 6fdff5945c8a0..59f27ea928b42 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -680,6 +680,15 @@ struct drm_get_cap {
>   */
>  #define DRM_CLIENT_CAP_ATOMIC	3
>  
> +/**
> + * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS
> + *
> + * If set to 1, the DRM core will expose special connectors to be used for
> + * writing back to memory the scene setup in the commit. Depends on client
> + * also supporting DRM_CLIENT_CAP_ATOMIC
> + */
> +#define DRM_CLIENT_CAP_WRITEBACK_CONNECTORS	4
> +
>  /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */
>  struct drm_set_client_cap {
>  	__u64 capability;

~Maarten
Liviu Dudau May 23, 2018, 12:27 p.m. UTC | #2
On Wed, May 23, 2018 at 11:34:32AM +0200, Maarten Lankhorst wrote:
> Op 18-05-18 om 17:17 schreef Liviu Dudau:
> > Due to the fact that writeback connectors behave in a special way
> > in DRM (they always report being disconnected) we might confuse some
> > userspace. Add a client capability for writeback connectors that will
> > filter them out for clients that don't understand the capability.
> >
> > Re-requested-by: Sean Paul <seanpaul@chromium.org>
> > Cc: Brian Starkey <brian.starkey@arm.com>
> > Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
> > ---
> >  drivers/gpu/drm/drm_ioctl.c       | 7 +++++++
> >  drivers/gpu/drm/drm_mode_config.c | 5 +++++
> >  include/drm/drm_file.h            | 7 +++++++
> >  include/uapi/drm/drm.h            | 9 +++++++++
> >  4 files changed, 28 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> > index af782911c505d..59951ff3e3630 100644
> > --- a/drivers/gpu/drm/drm_ioctl.c
> > +++ b/drivers/gpu/drm/drm_ioctl.c
> > @@ -325,6 +325,13 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
> >  		file_priv->atomic = req->value;
> >  		file_priv->universal_planes = req->value;
> >  		break;
> > +	case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
> > +		if (!file_priv->atomic || !drm_core_check_feature(dev, DRIVER_ATOMIC))
> > +			return -EINVAL;
> Wondering how you can set the atomic cap without DRIVER_ATOMIC. :)

Caps can only be set one at a time. I was trying to cater for the cases
where userspace can set the WRITEBACK_CONNECTORS client cap before or
after setting the atomic cap.

> 
> That part could be dropped I think. We should probably WARN when trying to create a writeback connector without the DRIVER_ATOMIC cap set.

I could still keep the check for file_priv->atomic being set when
accepting the DRM_CLIENT_CAP_WRITEBACK_CONNECTORS and would not need a
warn.

Best regards,
Liviu

> > +		if (req->value > 1)
> > +			return -EINVAL;
> > +		file_priv->writeback_connectors = req->value;
> > +		break;
> >  	default:
> >  		return -EINVAL;
> >  	}
> > diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> > index e5c653357024d..21e353bd3948e 100644
> > --- a/drivers/gpu/drm/drm_mode_config.c
> > +++ b/drivers/gpu/drm/drm_mode_config.c
> > @@ -145,6 +145,11 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
> >  	count = 0;
> >  	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
> >  	drm_for_each_connector_iter(connector, &conn_iter) {
> > +		/* only expose writeback connectors if userspace understands them */
> > +		if (!file_priv->writeback_connectors &&
> > +		    (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))
> > +			continue;
> > +
> >  		if (drm_lease_held(file_priv, connector->base.id)) {
> >  			if (count < card_res->count_connectors &&
> >  			    put_user(connector->base.id, connector_id + count)) {
> > diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> > index 5176c3797680c..2a09b3c8965c6 100644
> > --- a/include/drm/drm_file.h
> > +++ b/include/drm/drm_file.h
> > @@ -181,6 +181,13 @@ struct drm_file {
> >  	/** @atomic: True if client understands atomic properties. */
> >  	unsigned atomic:1;
> >  
> > +	/**
> > +	 * @writeback_connectors:
> > +	 *
> > +	 * True if client understands writeback connectors
> > +	 */
> > +	unsigned writeback_connectors:1;
> > +
> >  	/**
> >  	 * @is_master:
> >  	 *
> > diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> > index 6fdff5945c8a0..59f27ea928b42 100644
> > --- a/include/uapi/drm/drm.h
> > +++ b/include/uapi/drm/drm.h
> > @@ -680,6 +680,15 @@ struct drm_get_cap {
> >   */
> >  #define DRM_CLIENT_CAP_ATOMIC	3
> >  
> > +/**
> > + * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS
> > + *
> > + * If set to 1, the DRM core will expose special connectors to be used for
> > + * writing back to memory the scene setup in the commit. Depends on client
> > + * also supporting DRM_CLIENT_CAP_ATOMIC
> > + */
> > +#define DRM_CLIENT_CAP_WRITEBACK_CONNECTORS	4
> > +
> >  /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */
> >  struct drm_set_client_cap {
> >  	__u64 capability;
> 
> ~Maarten
>
Daniel Vetter May 24, 2018, 7:50 a.m. UTC | #3
On Wed, May 23, 2018 at 01:27:17PM +0100, Liviu Dudau wrote:
> On Wed, May 23, 2018 at 11:34:32AM +0200, Maarten Lankhorst wrote:
> > Op 18-05-18 om 17:17 schreef Liviu Dudau:
> > > Due to the fact that writeback connectors behave in a special way
> > > in DRM (they always report being disconnected) we might confuse some
> > > userspace. Add a client capability for writeback connectors that will
> > > filter them out for clients that don't understand the capability.
> > >
> > > Re-requested-by: Sean Paul <seanpaul@chromium.org>
> > > Cc: Brian Starkey <brian.starkey@arm.com>
> > > Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
> > > ---
> > >  drivers/gpu/drm/drm_ioctl.c       | 7 +++++++
> > >  drivers/gpu/drm/drm_mode_config.c | 5 +++++
> > >  include/drm/drm_file.h            | 7 +++++++
> > >  include/uapi/drm/drm.h            | 9 +++++++++
> > >  4 files changed, 28 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> > > index af782911c505d..59951ff3e3630 100644
> > > --- a/drivers/gpu/drm/drm_ioctl.c
> > > +++ b/drivers/gpu/drm/drm_ioctl.c
> > > @@ -325,6 +325,13 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
> > >  		file_priv->atomic = req->value;
> > >  		file_priv->universal_planes = req->value;
> > >  		break;
> > > +	case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
> > > +		if (!file_priv->atomic || !drm_core_check_feature(dev, DRIVER_ATOMIC))
> > > +			return -EINVAL;
> > Wondering how you can set the atomic cap without DRIVER_ATOMIC. :)
> 
> Caps can only be set one at a time. I was trying to cater for the cases
> where userspace can set the WRITEBACK_CONNECTORS client cap before or
> after setting the atomic cap.

The way we usually solve this is that if there's a dependency in caps, we
set them all. E.g. atomic above also sets universal planes. I recommend we
do the same for writeback.

> > That part could be dropped I think. We should probably WARN when trying to create a writeback connector without the DRIVER_ATOMIC cap set.
> 
> I could still keep the check for file_priv->atomic being set when
> accepting the DRM_CLIENT_CAP_WRITEBACK_CONNECTORS and would not need a
> warn.

Or this.
-Daniel

> 
> Best regards,
> Liviu
> 
> > > +		if (req->value > 1)
> > > +			return -EINVAL;
> > > +		file_priv->writeback_connectors = req->value;
> > > +		break;
> > >  	default:
> > >  		return -EINVAL;
> > >  	}
> > > diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> > > index e5c653357024d..21e353bd3948e 100644
> > > --- a/drivers/gpu/drm/drm_mode_config.c
> > > +++ b/drivers/gpu/drm/drm_mode_config.c
> > > @@ -145,6 +145,11 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
> > >  	count = 0;
> > >  	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
> > >  	drm_for_each_connector_iter(connector, &conn_iter) {
> > > +		/* only expose writeback connectors if userspace understands them */
> > > +		if (!file_priv->writeback_connectors &&
> > > +		    (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))
> > > +			continue;
> > > +
> > >  		if (drm_lease_held(file_priv, connector->base.id)) {
> > >  			if (count < card_res->count_connectors &&
> > >  			    put_user(connector->base.id, connector_id + count)) {
> > > diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> > > index 5176c3797680c..2a09b3c8965c6 100644
> > > --- a/include/drm/drm_file.h
> > > +++ b/include/drm/drm_file.h
> > > @@ -181,6 +181,13 @@ struct drm_file {
> > >  	/** @atomic: True if client understands atomic properties. */
> > >  	unsigned atomic:1;
> > >  
> > > +	/**
> > > +	 * @writeback_connectors:
> > > +	 *
> > > +	 * True if client understands writeback connectors
> > > +	 */
> > > +	unsigned writeback_connectors:1;
> > > +
> > >  	/**
> > >  	 * @is_master:
> > >  	 *
> > > diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> > > index 6fdff5945c8a0..59f27ea928b42 100644
> > > --- a/include/uapi/drm/drm.h
> > > +++ b/include/uapi/drm/drm.h
> > > @@ -680,6 +680,15 @@ struct drm_get_cap {
> > >   */
> > >  #define DRM_CLIENT_CAP_ATOMIC	3
> > >  
> > > +/**
> > > + * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS
> > > + *
> > > + * If set to 1, the DRM core will expose special connectors to be used for
> > > + * writing back to memory the scene setup in the commit. Depends on client
> > > + * also supporting DRM_CLIENT_CAP_ATOMIC
> > > + */
> > > +#define DRM_CLIENT_CAP_WRITEBACK_CONNECTORS	4
> > > +
> > >  /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */
> > >  struct drm_set_client_cap {
> > >  	__u64 capability;
> > 
> > ~Maarten
> > 
> 
> -- 
> ====================
> | I would like to |
> | fix the world,  |
> | but they're not |
> | giving me the   |
>  \ source code!  /
>   ---------------
>     ¯\_(ツ)_/¯
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index af782911c505d..59951ff3e3630 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -325,6 +325,13 @@  drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
 		file_priv->atomic = req->value;
 		file_priv->universal_planes = req->value;
 		break;
+	case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
+		if (!file_priv->atomic || !drm_core_check_feature(dev, DRIVER_ATOMIC))
+			return -EINVAL;
+		if (req->value > 1)
+			return -EINVAL;
+		file_priv->writeback_connectors = req->value;
+		break;
 	default:
 		return -EINVAL;
 	}
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index e5c653357024d..21e353bd3948e 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -145,6 +145,11 @@  int drm_mode_getresources(struct drm_device *dev, void *data,
 	count = 0;
 	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
 	drm_for_each_connector_iter(connector, &conn_iter) {
+		/* only expose writeback connectors if userspace understands them */
+		if (!file_priv->writeback_connectors &&
+		    (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))
+			continue;
+
 		if (drm_lease_held(file_priv, connector->base.id)) {
 			if (count < card_res->count_connectors &&
 			    put_user(connector->base.id, connector_id + count)) {
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 5176c3797680c..2a09b3c8965c6 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -181,6 +181,13 @@  struct drm_file {
 	/** @atomic: True if client understands atomic properties. */
 	unsigned atomic:1;
 
+	/**
+	 * @writeback_connectors:
+	 *
+	 * True if client understands writeback connectors
+	 */
+	unsigned writeback_connectors:1;
+
 	/**
 	 * @is_master:
 	 *
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index 6fdff5945c8a0..59f27ea928b42 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -680,6 +680,15 @@  struct drm_get_cap {
  */
 #define DRM_CLIENT_CAP_ATOMIC	3
 
+/**
+ * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS
+ *
+ * If set to 1, the DRM core will expose special connectors to be used for
+ * writing back to memory the scene setup in the commit. Depends on client
+ * also supporting DRM_CLIENT_CAP_ATOMIC
+ */
+#define DRM_CLIENT_CAP_WRITEBACK_CONNECTORS	4
+
 /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */
 struct drm_set_client_cap {
 	__u64 capability;