diff mbox series

[WIP,06/15] drm/i915: Keep malloc references to MST ports

Message ID 20181214012604.13746-7-lyude@redhat.com (mailing list archive)
State New, archived
Headers show
Series MST refcounting/atomic helpers cleanup | expand

Commit Message

Lyude Paul Dec. 14, 2018, 1:25 a.m. UTC
So that the ports stay around until we've destroyed the connectors, in
order to ensure that we don't pass an invalid pointer to any MST helpers
once we introduce the new MST VCPI helpers.

Signed-off-by: Lyude Paul <lyude@redhat.com>
---
 drivers/gpu/drm/i915/intel_connector.c | 4 ++++
 drivers/gpu/drm/i915/intel_dp_mst.c    | 2 ++
 2 files changed, 6 insertions(+)

Comments

Daniel Vetter Dec. 14, 2018, 9:32 a.m. UTC | #1
On Thu, Dec 13, 2018 at 08:25:35PM -0500, Lyude Paul wrote:
> So that the ports stay around until we've destroyed the connectors, in
> order to ensure that we don't pass an invalid pointer to any MST helpers
> once we introduce the new MST VCPI helpers.
> 
> Signed-off-by: Lyude Paul <lyude@redhat.com>
> ---
>  drivers/gpu/drm/i915/intel_connector.c | 4 ++++
>  drivers/gpu/drm/i915/intel_dp_mst.c    | 2 ++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_connector.c b/drivers/gpu/drm/i915/intel_connector.c
> index 18e370f607bc..37d2c644f4b8 100644
> --- a/drivers/gpu/drm/i915/intel_connector.c
> +++ b/drivers/gpu/drm/i915/intel_connector.c
> @@ -95,6 +95,10 @@ void intel_connector_destroy(struct drm_connector *connector)
>  	intel_panel_fini(&intel_connector->panel);
>  
>  	drm_connector_cleanup(connector);
> +
> +	if (intel_connector->port)

We set this as the first thing in intel_dp_add_mst_connector, so this
check isn't doing anything.

> +		drm_dp_mst_put_port_malloc(intel_connector->port);
> +
>  	kfree(connector);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> index f05427b74e34..4d6ced34d465 100644
> --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> @@ -484,6 +484,8 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
>  	if (ret)
>  		goto err;
>  
> +	drm_dp_mst_get_port_malloc(port);

Needs to be moved up where we assing intel_connector->port, or it'll
underflow on cleanup on error paths.

> +
>  	return connector;
>  
>  err:
> -- 
> 2.19.2
>
Lyude Paul Dec. 18, 2018, 9:52 p.m. UTC | #2
On Fri, 2018-12-14 at 10:32 +0100, Daniel Vetter wrote:
> On Thu, Dec 13, 2018 at 08:25:35PM -0500, Lyude Paul wrote:
> > So that the ports stay around until we've destroyed the connectors, in
> > order to ensure that we don't pass an invalid pointer to any MST helpers
> > once we introduce the new MST VCPI helpers.
> > 
> > Signed-off-by: Lyude Paul <lyude@redhat.com>
> > ---
> >  drivers/gpu/drm/i915/intel_connector.c | 4 ++++
> >  drivers/gpu/drm/i915/intel_dp_mst.c    | 2 ++
> >  2 files changed, 6 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_connector.c
> > b/drivers/gpu/drm/i915/intel_connector.c
> > index 18e370f607bc..37d2c644f4b8 100644
> > --- a/drivers/gpu/drm/i915/intel_connector.c
> > +++ b/drivers/gpu/drm/i915/intel_connector.c
> > @@ -95,6 +95,10 @@ void intel_connector_destroy(struct drm_connector
> > *connector)
> >  	intel_panel_fini(&intel_connector->panel);
> >  
> >  	drm_connector_cleanup(connector);
> > +
> > +	if (intel_connector->port)
> 
> We set this as the first thing in intel_dp_add_mst_connector, so this
> check isn't doing anything.

I think this comment might be a mistake? intel_connector_destroy() is shared
by all of the intel connectors, so some may not have a value in
intel_connector->port. I can move it to it's own destroy callback for MST if
you would prefer though.
> 
> > +		drm_dp_mst_put_port_malloc(intel_connector->port);
> > +
> >  	kfree(connector);
> >  }
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c
> > b/drivers/gpu/drm/i915/intel_dp_mst.c
> > index f05427b74e34..4d6ced34d465 100644
> > --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> > @@ -484,6 +484,8 @@ static struct drm_connector
> > *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
> >  	if (ret)
> >  		goto err;
> >  
> > +	drm_dp_mst_get_port_malloc(port);
> 
> Needs to be moved up where we assing intel_connector->port, or it'll
> underflow on cleanup on error paths.
> 
> > +
> >  	return connector;
> >  
> >  err:
> > -- 
> > 2.19.2
> >
Daniel Vetter Dec. 19, 2018, 1:20 p.m. UTC | #3
On Tue, Dec 18, 2018 at 04:52:24PM -0500, Lyude Paul wrote:
> On Fri, 2018-12-14 at 10:32 +0100, Daniel Vetter wrote:
> > On Thu, Dec 13, 2018 at 08:25:35PM -0500, Lyude Paul wrote:
> > > So that the ports stay around until we've destroyed the connectors, in
> > > order to ensure that we don't pass an invalid pointer to any MST helpers
> > > once we introduce the new MST VCPI helpers.
> > > 
> > > Signed-off-by: Lyude Paul <lyude@redhat.com>
> > > ---
> > >  drivers/gpu/drm/i915/intel_connector.c | 4 ++++
> > >  drivers/gpu/drm/i915/intel_dp_mst.c    | 2 ++
> > >  2 files changed, 6 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/intel_connector.c
> > > b/drivers/gpu/drm/i915/intel_connector.c
> > > index 18e370f607bc..37d2c644f4b8 100644
> > > --- a/drivers/gpu/drm/i915/intel_connector.c
> > > +++ b/drivers/gpu/drm/i915/intel_connector.c
> > > @@ -95,6 +95,10 @@ void intel_connector_destroy(struct drm_connector
> > > *connector)
> > >  	intel_panel_fini(&intel_connector->panel);
> > >  
> > >  	drm_connector_cleanup(connector);
> > > +
> > > +	if (intel_connector->port)
> > 
> > We set this as the first thing in intel_dp_add_mst_connector, so this
> > check isn't doing anything.
> 
> I think this comment might be a mistake? intel_connector_destroy() is shared
> by all of the intel connectors, so some may not have a value in
> intel_connector->port. I can move it to it's own destroy callback for MST if
> you would prefer though.

Oops, didn't look at the patch carefully enough. I think a
intel_dp_mst_connector_destroy would be useful in this case. But a bit a
bikeshed, so up to you.
-Daniel

> > 
> > > +		drm_dp_mst_put_port_malloc(intel_connector->port);
> > > +
> > >  	kfree(connector);
> > >  }
> > >  
> > > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c
> > > b/drivers/gpu/drm/i915/intel_dp_mst.c
> > > index f05427b74e34..4d6ced34d465 100644
> > > --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> > > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> > > @@ -484,6 +484,8 @@ static struct drm_connector
> > > *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
> > >  	if (ret)
> > >  		goto err;
> > >  
> > > +	drm_dp_mst_get_port_malloc(port);
> > 
> > Needs to be moved up where we assing intel_connector->port, or it'll
> > underflow on cleanup on error paths.
> > 
> > > +
> > >  	return connector;
> > >  
> > >  err:
> > > -- 
> > > 2.19.2
> > > 
> -- 
> Cheers,
> 	Lyude Paul
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/intel_connector.c b/drivers/gpu/drm/i915/intel_connector.c
index 18e370f607bc..37d2c644f4b8 100644
--- a/drivers/gpu/drm/i915/intel_connector.c
+++ b/drivers/gpu/drm/i915/intel_connector.c
@@ -95,6 +95,10 @@  void intel_connector_destroy(struct drm_connector *connector)
 	intel_panel_fini(&intel_connector->panel);
 
 	drm_connector_cleanup(connector);
+
+	if (intel_connector->port)
+		drm_dp_mst_put_port_malloc(intel_connector->port);
+
 	kfree(connector);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index f05427b74e34..4d6ced34d465 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -484,6 +484,8 @@  static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
 	if (ret)
 		goto err;
 
+	drm_dp_mst_get_port_malloc(port);
+
 	return connector;
 
 err: