Re: [PATCH] drm: atomic: Clarify documentation around drm_atomic_crtc_needs_modeset
On Thu, Oct 13, 2016 at 10:54:51AM -0400, Alex Deucher wrote: > On Thu, Oct 13, 2016 at 5:47 AM, Brian Starkeywrote: > > Add some additional comments to more explicitly describe the meaning and > > usage of the three CRTC modeset detection booleans: mode_changed, > > connectors_changed and active_changed. > > > > Suggested-by: Daniel Vetter > > Signed-off-by: Brian Starkey > > --- > > > > Hi Daniel, > > > > I guess I asked for this one :-), please just check my understanding > > is correct. > > > > The whole thread was very enlightening for me with respect to those > flags as well. The patch looks good to me. > Acked-by: Alex Deucher Applied to drm-misc, thanks. -Daniel > > > Thanks, > > Brian > > > > drivers/gpu/drm/drm_atomic_helper.c |9 + > > include/drm/drm_atomic.h| 11 ++- > > include/drm/drm_crtc.h |5 + > > 3 files changed, 20 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c > > b/drivers/gpu/drm/drm_atomic_helper.c > > index 78ea735..fb4071a 100644 > > --- a/drivers/gpu/drm/drm_atomic_helper.c > > +++ b/drivers/gpu/drm/drm_atomic_helper.c > > @@ -458,10 +458,11 @@ mode_fixup(struct drm_atomic_state *state) > > * removed from the crtc. > > * crtc_state->active_changed is set when crtc_state->active changes, > > * which is used for dpms. > > + * See also: drm_atomic_crtc_needs_modeset() > > * > > * IMPORTANT: > > * > > - * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks > > if a > > + * Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if > > a > > * plane update can't be done without a full modeset) _must_ call this > > function > > * afterwards after that change. It is permitted to call this function > > multiple > > * times for the same update, e.g. when the ->atomic_check functions > > depend upon > > @@ -510,9 +511,9 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, > > > > for_each_connector_in_state(state, connector, connector_state, i) { > > /* > > -* This only sets crtc->mode_changed for routing changes, > > -* drivers must set crtc->mode_changed themselves when > > connector > > -* properties need to be updated. > > +* This only sets crtc->connectors_changed for routing > > changes, > > +* drivers must set crtc->connectors_changed themselves when > > +* connector properties need to be updated. > > */ > > ret = update_connector_routing(state, connector, > >connector_state); > > diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h > > index d9aff06..1ce255f 100644 > > --- a/include/drm/drm_atomic.h > > +++ b/include/drm/drm_atomic.h > > @@ -368,8 +368,17 @@ int __must_check drm_atomic_nonblocking_commit(struct > > drm_atomic_state *state); > > * > > * To give drivers flexibility struct _crtc_state has 3 booleans to > > track > > * whether the state CRTC changed enough to need a full modeset cycle: > > - * connectors_changed, mode_changed and active_change. This helper simply > > + * connectors_changed, mode_changed and active_changed. This helper simply > > * combines these three to compute the overall need for a modeset for > > @state. > > + * > > + * The atomic helper code sets these booleans, but drivers can and should > > + * change them appropriately to accurately represent whether a modeset is > > + * really needed. In general, drivers should avoid full modesets whenever > > + * possible. > > + * > > + * For example if the CRTC mode has changed, and the hardware is able to > > enact > > + * the requested mode change without going through a full modeset, the > > driver > > + * should clear mode_changed during its ->atomic_check. > > */ > > static inline bool > > drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state) > > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > > index c4a3164..1f094d2 100644 > > --- a/include/drm/drm_crtc.h > > +++ b/include/drm/drm_crtc.h > > @@ -116,6 +116,11 @@ struct drm_plane_helper_funcs; > > * never return in a failure from the ->atomic_check callback. Userspace > > assumes > > * that a DPMS On will always succeed. In other words: @enable controls > > resource > > * assignment, @active controls the actual hardware state. > > + * > > + * The three booleans active_changed, connectors_changed and mode_changed > > are > > + * intended to indicate whether a full modeset is needed, rather than > > strictly > > + * describing what has changed in a commit. > > + * See also: drm_atomic_crtc_needs_modeset() > > */ > > struct drm_crtc_state { > > struct drm_crtc *crtc; > > -- > > 1.7.9.5 > > > >
Re: [PATCH] drm: atomic: Clarify documentation around drm_atomic_crtc_needs_modeset
On Thu, Oct 13, 2016 at 10:54:51AM -0400, Alex Deucher wrote: > On Thu, Oct 13, 2016 at 5:47 AM, Brian Starkey wrote: > > Add some additional comments to more explicitly describe the meaning and > > usage of the three CRTC modeset detection booleans: mode_changed, > > connectors_changed and active_changed. > > > > Suggested-by: Daniel Vetter > > Signed-off-by: Brian Starkey > > --- > > > > Hi Daniel, > > > > I guess I asked for this one :-), please just check my understanding > > is correct. > > > > The whole thread was very enlightening for me with respect to those > flags as well. The patch looks good to me. > Acked-by: Alex Deucher Applied to drm-misc, thanks. -Daniel > > > Thanks, > > Brian > > > > drivers/gpu/drm/drm_atomic_helper.c |9 + > > include/drm/drm_atomic.h| 11 ++- > > include/drm/drm_crtc.h |5 + > > 3 files changed, 20 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c > > b/drivers/gpu/drm/drm_atomic_helper.c > > index 78ea735..fb4071a 100644 > > --- a/drivers/gpu/drm/drm_atomic_helper.c > > +++ b/drivers/gpu/drm/drm_atomic_helper.c > > @@ -458,10 +458,11 @@ mode_fixup(struct drm_atomic_state *state) > > * removed from the crtc. > > * crtc_state->active_changed is set when crtc_state->active changes, > > * which is used for dpms. > > + * See also: drm_atomic_crtc_needs_modeset() > > * > > * IMPORTANT: > > * > > - * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks > > if a > > + * Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if > > a > > * plane update can't be done without a full modeset) _must_ call this > > function > > * afterwards after that change. It is permitted to call this function > > multiple > > * times for the same update, e.g. when the ->atomic_check functions > > depend upon > > @@ -510,9 +511,9 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, > > > > for_each_connector_in_state(state, connector, connector_state, i) { > > /* > > -* This only sets crtc->mode_changed for routing changes, > > -* drivers must set crtc->mode_changed themselves when > > connector > > -* properties need to be updated. > > +* This only sets crtc->connectors_changed for routing > > changes, > > +* drivers must set crtc->connectors_changed themselves when > > +* connector properties need to be updated. > > */ > > ret = update_connector_routing(state, connector, > >connector_state); > > diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h > > index d9aff06..1ce255f 100644 > > --- a/include/drm/drm_atomic.h > > +++ b/include/drm/drm_atomic.h > > @@ -368,8 +368,17 @@ int __must_check drm_atomic_nonblocking_commit(struct > > drm_atomic_state *state); > > * > > * To give drivers flexibility struct _crtc_state has 3 booleans to > > track > > * whether the state CRTC changed enough to need a full modeset cycle: > > - * connectors_changed, mode_changed and active_change. This helper simply > > + * connectors_changed, mode_changed and active_changed. This helper simply > > * combines these three to compute the overall need for a modeset for > > @state. > > + * > > + * The atomic helper code sets these booleans, but drivers can and should > > + * change them appropriately to accurately represent whether a modeset is > > + * really needed. In general, drivers should avoid full modesets whenever > > + * possible. > > + * > > + * For example if the CRTC mode has changed, and the hardware is able to > > enact > > + * the requested mode change without going through a full modeset, the > > driver > > + * should clear mode_changed during its ->atomic_check. > > */ > > static inline bool > > drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state) > > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > > index c4a3164..1f094d2 100644 > > --- a/include/drm/drm_crtc.h > > +++ b/include/drm/drm_crtc.h > > @@ -116,6 +116,11 @@ struct drm_plane_helper_funcs; > > * never return in a failure from the ->atomic_check callback. Userspace > > assumes > > * that a DPMS On will always succeed. In other words: @enable controls > > resource > > * assignment, @active controls the actual hardware state. > > + * > > + * The three booleans active_changed, connectors_changed and mode_changed > > are > > + * intended to indicate whether a full modeset is needed, rather than > > strictly > > + * describing what has changed in a commit. > > + * See also: drm_atomic_crtc_needs_modeset() > > */ > > struct drm_crtc_state { > > struct drm_crtc *crtc; > > -- > > 1.7.9.5 > > > > ___ > > dri-devel mailing list > > dri-de...@lists.freedesktop.org > >
Re: [PATCH] drm: atomic: Clarify documentation around drm_atomic_crtc_needs_modeset
On Thu, Oct 13, 2016 at 5:47 AM, Brian Starkeywrote: > Add some additional comments to more explicitly describe the meaning and > usage of the three CRTC modeset detection booleans: mode_changed, > connectors_changed and active_changed. > > Suggested-by: Daniel Vetter > Signed-off-by: Brian Starkey > --- > > Hi Daniel, > > I guess I asked for this one :-), please just check my understanding > is correct. > The whole thread was very enlightening for me with respect to those flags as well. The patch looks good to me. Acked-by: Alex Deucher > Thanks, > Brian > > drivers/gpu/drm/drm_atomic_helper.c |9 + > include/drm/drm_atomic.h| 11 ++- > include/drm/drm_crtc.h |5 + > 3 files changed, 20 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c > b/drivers/gpu/drm/drm_atomic_helper.c > index 78ea735..fb4071a 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -458,10 +458,11 @@ mode_fixup(struct drm_atomic_state *state) > * removed from the crtc. > * crtc_state->active_changed is set when crtc_state->active changes, > * which is used for dpms. > + * See also: drm_atomic_crtc_needs_modeset() > * > * IMPORTANT: > * > - * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks > if a > + * Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if a > * plane update can't be done without a full modeset) _must_ call this > function > * afterwards after that change. It is permitted to call this function > multiple > * times for the same update, e.g. when the ->atomic_check functions depend > upon > @@ -510,9 +511,9 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, > > for_each_connector_in_state(state, connector, connector_state, i) { > /* > -* This only sets crtc->mode_changed for routing changes, > -* drivers must set crtc->mode_changed themselves when > connector > -* properties need to be updated. > +* This only sets crtc->connectors_changed for routing > changes, > +* drivers must set crtc->connectors_changed themselves when > +* connector properties need to be updated. > */ > ret = update_connector_routing(state, connector, >connector_state); > diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h > index d9aff06..1ce255f 100644 > --- a/include/drm/drm_atomic.h > +++ b/include/drm/drm_atomic.h > @@ -368,8 +368,17 @@ int __must_check drm_atomic_nonblocking_commit(struct > drm_atomic_state *state); > * > * To give drivers flexibility struct _crtc_state has 3 booleans to track > * whether the state CRTC changed enough to need a full modeset cycle: > - * connectors_changed, mode_changed and active_change. This helper simply > + * connectors_changed, mode_changed and active_changed. This helper simply > * combines these three to compute the overall need for a modeset for @state. > + * > + * The atomic helper code sets these booleans, but drivers can and should > + * change them appropriately to accurately represent whether a modeset is > + * really needed. In general, drivers should avoid full modesets whenever > + * possible. > + * > + * For example if the CRTC mode has changed, and the hardware is able to > enact > + * the requested mode change without going through a full modeset, the driver > + * should clear mode_changed during its ->atomic_check. > */ > static inline bool > drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state) > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index c4a3164..1f094d2 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -116,6 +116,11 @@ struct drm_plane_helper_funcs; > * never return in a failure from the ->atomic_check callback. Userspace > assumes > * that a DPMS On will always succeed. In other words: @enable controls > resource > * assignment, @active controls the actual hardware state. > + * > + * The three booleans active_changed, connectors_changed and mode_changed are > + * intended to indicate whether a full modeset is needed, rather than > strictly > + * describing what has changed in a commit. > + * See also: drm_atomic_crtc_needs_modeset() > */ > struct drm_crtc_state { > struct drm_crtc *crtc; > -- > 1.7.9.5 > > ___ > dri-devel mailing list > dri-de...@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] drm: atomic: Clarify documentation around drm_atomic_crtc_needs_modeset
On Thu, Oct 13, 2016 at 5:47 AM, Brian Starkey wrote: > Add some additional comments to more explicitly describe the meaning and > usage of the three CRTC modeset detection booleans: mode_changed, > connectors_changed and active_changed. > > Suggested-by: Daniel Vetter > Signed-off-by: Brian Starkey > --- > > Hi Daniel, > > I guess I asked for this one :-), please just check my understanding > is correct. > The whole thread was very enlightening for me with respect to those flags as well. The patch looks good to me. Acked-by: Alex Deucher > Thanks, > Brian > > drivers/gpu/drm/drm_atomic_helper.c |9 + > include/drm/drm_atomic.h| 11 ++- > include/drm/drm_crtc.h |5 + > 3 files changed, 20 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c > b/drivers/gpu/drm/drm_atomic_helper.c > index 78ea735..fb4071a 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -458,10 +458,11 @@ mode_fixup(struct drm_atomic_state *state) > * removed from the crtc. > * crtc_state->active_changed is set when crtc_state->active changes, > * which is used for dpms. > + * See also: drm_atomic_crtc_needs_modeset() > * > * IMPORTANT: > * > - * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks > if a > + * Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if a > * plane update can't be done without a full modeset) _must_ call this > function > * afterwards after that change. It is permitted to call this function > multiple > * times for the same update, e.g. when the ->atomic_check functions depend > upon > @@ -510,9 +511,9 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, > > for_each_connector_in_state(state, connector, connector_state, i) { > /* > -* This only sets crtc->mode_changed for routing changes, > -* drivers must set crtc->mode_changed themselves when > connector > -* properties need to be updated. > +* This only sets crtc->connectors_changed for routing > changes, > +* drivers must set crtc->connectors_changed themselves when > +* connector properties need to be updated. > */ > ret = update_connector_routing(state, connector, >connector_state); > diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h > index d9aff06..1ce255f 100644 > --- a/include/drm/drm_atomic.h > +++ b/include/drm/drm_atomic.h > @@ -368,8 +368,17 @@ int __must_check drm_atomic_nonblocking_commit(struct > drm_atomic_state *state); > * > * To give drivers flexibility struct _crtc_state has 3 booleans to track > * whether the state CRTC changed enough to need a full modeset cycle: > - * connectors_changed, mode_changed and active_change. This helper simply > + * connectors_changed, mode_changed and active_changed. This helper simply > * combines these three to compute the overall need for a modeset for @state. > + * > + * The atomic helper code sets these booleans, but drivers can and should > + * change them appropriately to accurately represent whether a modeset is > + * really needed. In general, drivers should avoid full modesets whenever > + * possible. > + * > + * For example if the CRTC mode has changed, and the hardware is able to > enact > + * the requested mode change without going through a full modeset, the driver > + * should clear mode_changed during its ->atomic_check. > */ > static inline bool > drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state) > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index c4a3164..1f094d2 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -116,6 +116,11 @@ struct drm_plane_helper_funcs; > * never return in a failure from the ->atomic_check callback. Userspace > assumes > * that a DPMS On will always succeed. In other words: @enable controls > resource > * assignment, @active controls the actual hardware state. > + * > + * The three booleans active_changed, connectors_changed and mode_changed are > + * intended to indicate whether a full modeset is needed, rather than > strictly > + * describing what has changed in a commit. > + * See also: drm_atomic_crtc_needs_modeset() > */ > struct drm_crtc_state { > struct drm_crtc *crtc; > -- > 1.7.9.5 > > ___ > dri-devel mailing list > dri-de...@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
[PATCH] drm: atomic: Clarify documentation around drm_atomic_crtc_needs_modeset
Add some additional comments to more explicitly describe the meaning and usage of the three CRTC modeset detection booleans: mode_changed, connectors_changed and active_changed. Suggested-by: Daniel VetterSigned-off-by: Brian Starkey --- Hi Daniel, I guess I asked for this one :-), please just check my understanding is correct. Thanks, Brian drivers/gpu/drm/drm_atomic_helper.c |9 + include/drm/drm_atomic.h| 11 ++- include/drm/drm_crtc.h |5 + 3 files changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 78ea735..fb4071a 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -458,10 +458,11 @@ mode_fixup(struct drm_atomic_state *state) * removed from the crtc. * crtc_state->active_changed is set when crtc_state->active changes, * which is used for dpms. + * See also: drm_atomic_crtc_needs_modeset() * * IMPORTANT: * - * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks if a + * Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if a * plane update can't be done without a full modeset) _must_ call this function * afterwards after that change. It is permitted to call this function multiple * times for the same update, e.g. when the ->atomic_check functions depend upon @@ -510,9 +511,9 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, for_each_connector_in_state(state, connector, connector_state, i) { /* -* This only sets crtc->mode_changed for routing changes, -* drivers must set crtc->mode_changed themselves when connector -* properties need to be updated. +* This only sets crtc->connectors_changed for routing changes, +* drivers must set crtc->connectors_changed themselves when +* connector properties need to be updated. */ ret = update_connector_routing(state, connector, connector_state); diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index d9aff06..1ce255f 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -368,8 +368,17 @@ int __must_check drm_atomic_nonblocking_commit(struct drm_atomic_state *state); * * To give drivers flexibility struct _crtc_state has 3 booleans to track * whether the state CRTC changed enough to need a full modeset cycle: - * connectors_changed, mode_changed and active_change. This helper simply + * connectors_changed, mode_changed and active_changed. This helper simply * combines these three to compute the overall need for a modeset for @state. + * + * The atomic helper code sets these booleans, but drivers can and should + * change them appropriately to accurately represent whether a modeset is + * really needed. In general, drivers should avoid full modesets whenever + * possible. + * + * For example if the CRTC mode has changed, and the hardware is able to enact + * the requested mode change without going through a full modeset, the driver + * should clear mode_changed during its ->atomic_check. */ static inline bool drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state) diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index c4a3164..1f094d2 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -116,6 +116,11 @@ struct drm_plane_helper_funcs; * never return in a failure from the ->atomic_check callback. Userspace assumes * that a DPMS On will always succeed. In other words: @enable controls resource * assignment, @active controls the actual hardware state. + * + * The three booleans active_changed, connectors_changed and mode_changed are + * intended to indicate whether a full modeset is needed, rather than strictly + * describing what has changed in a commit. + * See also: drm_atomic_crtc_needs_modeset() */ struct drm_crtc_state { struct drm_crtc *crtc; -- 1.7.9.5
[PATCH] drm: atomic: Clarify documentation around drm_atomic_crtc_needs_modeset
Add some additional comments to more explicitly describe the meaning and usage of the three CRTC modeset detection booleans: mode_changed, connectors_changed and active_changed. Suggested-by: Daniel Vetter Signed-off-by: Brian Starkey --- Hi Daniel, I guess I asked for this one :-), please just check my understanding is correct. Thanks, Brian drivers/gpu/drm/drm_atomic_helper.c |9 + include/drm/drm_atomic.h| 11 ++- include/drm/drm_crtc.h |5 + 3 files changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 78ea735..fb4071a 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -458,10 +458,11 @@ mode_fixup(struct drm_atomic_state *state) * removed from the crtc. * crtc_state->active_changed is set when crtc_state->active changes, * which is used for dpms. + * See also: drm_atomic_crtc_needs_modeset() * * IMPORTANT: * - * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks if a + * Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if a * plane update can't be done without a full modeset) _must_ call this function * afterwards after that change. It is permitted to call this function multiple * times for the same update, e.g. when the ->atomic_check functions depend upon @@ -510,9 +511,9 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, for_each_connector_in_state(state, connector, connector_state, i) { /* -* This only sets crtc->mode_changed for routing changes, -* drivers must set crtc->mode_changed themselves when connector -* properties need to be updated. +* This only sets crtc->connectors_changed for routing changes, +* drivers must set crtc->connectors_changed themselves when +* connector properties need to be updated. */ ret = update_connector_routing(state, connector, connector_state); diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index d9aff06..1ce255f 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -368,8 +368,17 @@ int __must_check drm_atomic_nonblocking_commit(struct drm_atomic_state *state); * * To give drivers flexibility struct _crtc_state has 3 booleans to track * whether the state CRTC changed enough to need a full modeset cycle: - * connectors_changed, mode_changed and active_change. This helper simply + * connectors_changed, mode_changed and active_changed. This helper simply * combines these three to compute the overall need for a modeset for @state. + * + * The atomic helper code sets these booleans, but drivers can and should + * change them appropriately to accurately represent whether a modeset is + * really needed. In general, drivers should avoid full modesets whenever + * possible. + * + * For example if the CRTC mode has changed, and the hardware is able to enact + * the requested mode change without going through a full modeset, the driver + * should clear mode_changed during its ->atomic_check. */ static inline bool drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state) diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index c4a3164..1f094d2 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -116,6 +116,11 @@ struct drm_plane_helper_funcs; * never return in a failure from the ->atomic_check callback. Userspace assumes * that a DPMS On will always succeed. In other words: @enable controls resource * assignment, @active controls the actual hardware state. + * + * The three booleans active_changed, connectors_changed and mode_changed are + * intended to indicate whether a full modeset is needed, rather than strictly + * describing what has changed in a commit. + * See also: drm_atomic_crtc_needs_modeset() */ struct drm_crtc_state { struct drm_crtc *crtc; -- 1.7.9.5