| Message ID | 1461722609-32474-3-git-send-email-airlied@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 27 April 2016 at 03:03, Dave Airlie <airlied@gmail.com> wrote: > diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c > index 66ca313..29b7835 100644 > --- a/drivers/gpu/drm/drm_crtc_helper.c > +++ b/drivers/gpu/drm/drm_crtc_helper.c > @@ -456,6 +456,9 @@ drm_crtc_helper_disable(struct drm_crtc *crtc) > * between them is henceforth no longer available. > */ > connector->dpms = DRM_MODE_DPMS_OFF; > + > + /* we keep a reference while the encoder is bound */ > + drm_connector_unreference(connector); > } > } > > @@ -635,9 +638,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set) > mode_changed = true; > /* If the encoder is reused for another connector, then > * the appropriate crtc will be set later. > + * take a reference only if we haven't had an encoder before. > */ > if (connector->encoder) > connector->encoder->crtc = NULL; > + else > + drm_connector_reference(connector); > connector->encoder = new_encoder; > } > } This new ref leaks in the if (fail) goto fail path below, and I can't quite convince myself that it's correct in the case where they share an encoder. How about this: - unconditionally ref every connector in set->connectors before doing anything which can fail - on successful exit, unconditionally unref every connector in save_connectors - in the fail label, unconditionally unref every connector in set->connectors Not quite as efficient as trying to do the only-ref-on-change dance, but much easier to prove correct, as well as matching the atomic state approach, if you imagine save_connectors as the current state, and set->connectors as the new/req state. Plus, refcounting really isn't the expensive part of this operation. ;) Cheers, Daniel
On Wed, Apr 27, 2016 at 12:03:27PM +1000, Dave Airlie wrote: > From: Dave Airlie <airlied@redhat.com> > > This just takes a reference on the connector when we set a mode > in the non-atomic paths. > > Signed-off-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > drivers/gpu/drm/drm_crtc_helper.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c > index 66ca313..29b7835 100644 > --- a/drivers/gpu/drm/drm_crtc_helper.c > +++ b/drivers/gpu/drm/drm_crtc_helper.c > @@ -456,6 +456,9 @@ drm_crtc_helper_disable(struct drm_crtc *crtc) > * between them is henceforth no longer available. > */ > connector->dpms = DRM_MODE_DPMS_OFF; > + > + /* we keep a reference while the encoder is bound */ > + drm_connector_unreference(connector); > } > } > > @@ -635,9 +638,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set) > mode_changed = true; > /* If the encoder is reused for another connector, then > * the appropriate crtc will be set later. > + * take a reference only if we haven't had an encoder before. > */ > if (connector->encoder) > connector->encoder->crtc = NULL; > + else > + drm_connector_reference(connector); > connector->encoder = new_encoder; > } > } > -- > 2.5.5 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Wed, Apr 27, 2016 at 09:34:34AM +0200, Daniel Vetter wrote: > On Wed, Apr 27, 2016 at 12:03:27PM +1000, Dave Airlie wrote: > > From: Dave Airlie <airlied@redhat.com> > > > > This just takes a reference on the connector when we set a mode > > in the non-atomic paths. > > > > Signed-off-by: Dave Airlie <airlied@redhat.com> > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Ok I feel real silly now reading Daniel Stone's reply ;-) r-b retracted ... Cheers, Daniel > > > --- > > drivers/gpu/drm/drm_crtc_helper.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c > > index 66ca313..29b7835 100644 > > --- a/drivers/gpu/drm/drm_crtc_helper.c > > +++ b/drivers/gpu/drm/drm_crtc_helper.c > > @@ -456,6 +456,9 @@ drm_crtc_helper_disable(struct drm_crtc *crtc) > > * between them is henceforth no longer available. > > */ > > connector->dpms = DRM_MODE_DPMS_OFF; > > + > > + /* we keep a reference while the encoder is bound */ > > + drm_connector_unreference(connector); > > } > > } > > > > @@ -635,9 +638,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set) > > mode_changed = true; > > /* If the encoder is reused for another connector, then > > * the appropriate crtc will be set later. > > + * take a reference only if we haven't had an encoder before. > > */ > > if (connector->encoder) > > connector->encoder->crtc = NULL; > > + else > > + drm_connector_reference(connector); > > connector->encoder = new_encoder; > > } > > } > > -- > > 2.5.5 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 66ca313..29b7835 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -456,6 +456,9 @@ drm_crtc_helper_disable(struct drm_crtc *crtc) * between them is henceforth no longer available. */ connector->dpms = DRM_MODE_DPMS_OFF; + + /* we keep a reference while the encoder is bound */ + drm_connector_unreference(connector); } } @@ -635,9 +638,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set) mode_changed = true; /* If the encoder is reused for another connector, then * the appropriate crtc will be set later. + * take a reference only if we haven't had an encoder before. */ if (connector->encoder) connector->encoder->crtc = NULL; + else + drm_connector_reference(connector); connector->encoder = new_encoder; } }