diff mbox

[v2,7/8] drm: Use mode_valid() in atomic modeset

Message ID 61cee0404343a363c459a377d2ff53f5c13b1230.1494347165.git.joabreu@synopsys.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jose Abreu May 9, 2017, 5 p.m. UTC
This patches makes use of the new mode_valid() callbacks introduced
previously to validate the full video pipeline when modesetting.

This calls the connector->mode_valid(), encoder->mode_valid(),
bridge->mode_valid() and crtc->mode_valid() so that we can
make sure that the mode will be accepted in every components.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Archit Taneja <architt@codeaurora.org>
---

Changes v1->v2:
	- Removed call to connector->mode_valid (Ville, Daniel)
	- Change function name (Ville)
	- Use for_each_new_connector_in_state (Ville)
	- Do not validate if connector and mode didn't change (Ville)
	- Use new helpers to call mode_valid

 drivers/gpu/drm/drm_atomic_helper.c | 75 +++++++++++++++++++++++++++++++++++--
 1 file changed, 72 insertions(+), 3 deletions(-)

Comments

Archit Taneja May 10, 2017, 4:08 p.m. UTC | #1
On 5/9/2017 10:30 PM, Jose Abreu wrote:
> This patches makes use of the new mode_valid() callbacks introduced
> previously to validate the full video pipeline when modesetting.
> 
> This calls the connector->mode_valid(), encoder->mode_valid(),
> bridge->mode_valid() and crtc->mode_valid() so that we can
> make sure that the mode will be accepted in every components.
> 
> Signed-off-by: Jose Abreu <joabreu@synopsys.com>
> Cc: Carlos Palminha <palminha@synopsys.com>
> Cc: Alexey Brodkin <abrodkin@synopsys.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Dave Airlie <airlied@linux.ie>
> Cc: Andrzej Hajda <a.hajda@samsung.com>
> Cc: Archit Taneja <architt@codeaurora.org>
> ---
> 
> Changes v1->v2:
> 	- Removed call to connector->mode_valid (Ville, Daniel)
> 	- Change function name (Ville)
> 	- Use for_each_new_connector_in_state (Ville)
> 	- Do not validate if connector and mode didn't change (Ville)
> 	- Use new helpers to call mode_valid
> 
>   drivers/gpu/drm/drm_atomic_helper.c | 75 +++++++++++++++++++++++++++++++++++--
>   1 file changed, 72 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 8be9719..19d0ea1 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -452,6 +452,69 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
>   	return 0;
>   }
>   
> +static enum drm_mode_status mode_valid_path(struct drm_connector *connector,
> +					    struct drm_encoder *encoder,
> +					    struct drm_crtc *crtc,
> +					    struct drm_display_mode *mode)
> +{
> +	enum drm_mode_status ret;
> +
> +	ret = drm_encoder_mode_valid(encoder, mode);
> +	if (ret != MODE_OK) {
> +		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] mode_valid() failed\n",
> +				encoder->base.id, encoder->name);
> +		return ret;
> +	}
> +
> +	ret = drm_bridge_mode_valid(encoder->bridge, mode);
> +	if (ret != MODE_OK) {
> +		DRM_DEBUG_ATOMIC("[BRIDGE] mode_valid() failed\n");
> +		return ret;
> +	}
> +
> +	ret = drm_crtc_mode_valid(crtc, mode);
> +	if (ret != MODE_OK) {
> +		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode_valid() failed\n",
> +				crtc->base.id, crtc->name);
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +static int
> +mode_valid(struct drm_atomic_state *state)
> +{
> +	struct drm_connector_state *conn_state;
> +	struct drm_connector *connector;
> +	int i;
> +
> +	for_each_new_connector_in_state(state, connector, conn_state, i) {
> +		struct drm_encoder *encoder = conn_state->best_encoder;
> +		struct drm_crtc *crtc = conn_state->crtc;
> +		struct drm_crtc_state *crtc_state;
> +		enum drm_mode_status mode_status;
> +		struct drm_display_mode *mode;
> +
> +		if (!crtc || !encoder)
> +			continue;
> +
> +		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> +		if (!crtc_state)
> +			continue;
> +		if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
> +			continue;
> +
> +		mode = &crtc_state->mode;
> +
> +		mode_status = mode_valid_path(connector, encoder, crtc, mode);
> +		if (mode_status != MODE_OK)
> +			return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>   /**
>    * drm_atomic_helper_check_modeset - validate state object for modeset changes
>    * @dev: DRM device
> @@ -466,13 +529,15 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
>    * 2. &drm_connector_helper_funcs.atomic_check to validate the connector state.
>    * 3. If it's determined a modeset is needed then all connectors on the affected crtc
>    *    crtc are added and &drm_connector_helper_funcs.atomic_check is run on them.
> - * 4. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> - * 5. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
> + * 4. &drm_encoder_helper_funcs.mode_valid, &drm_bridge_funcs.mode_valid and
> + *    &drm_crtc_helper_funcs.mode_valid are called on the affected components.
> + * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> + * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
>    *    This function is only called when the encoder will be part of a configured crtc,
>    *    it must not be used for implementing connector property validation.
>    *    If this function is NULL, &drm_atomic_encoder_helper_funcs.mode_fixup is called
>    *    instead.
> - * 6. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with crtc constraints.
> + * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with crtc constraints.
>    *
>    * &drm_crtc_state.mode_changed is set when the input mode is changed.
>    * &drm_crtc_state.connectors_changed is set when a connector is added or
> @@ -617,6 +682,10 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
>   			return ret;
>   	}
>   
> +	ret = mode_valid(state);
> +	if (ret)
> +		return ret;
> +

Since we've ensured that the modes won't fail, can mode_fixup() and
the mode_fixup() ops for crtc/bridge/encoders be assured to not fail
too? This is assuming that all drivers have moved to using the new
mode_valid() ops correctly.

Thanks,
Archit

>   	return mode_fixup(state);
>   }
>   EXPORT_SYMBOL(drm_atomic_helper_check_modeset);
>
Daniel Vetter May 10, 2017, 5:55 p.m. UTC | #2
On Wed, May 10, 2017 at 09:38:00PM +0530, Archit Taneja wrote:
> 
> 
> On 5/9/2017 10:30 PM, Jose Abreu wrote:
> > This patches makes use of the new mode_valid() callbacks introduced
> > previously to validate the full video pipeline when modesetting.
> > 
> > This calls the connector->mode_valid(), encoder->mode_valid(),
> > bridge->mode_valid() and crtc->mode_valid() so that we can
> > make sure that the mode will be accepted in every components.
> > 
> > Signed-off-by: Jose Abreu <joabreu@synopsys.com>
> > Cc: Carlos Palminha <palminha@synopsys.com>
> > Cc: Alexey Brodkin <abrodkin@synopsys.com>
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Cc: Dave Airlie <airlied@linux.ie>
> > Cc: Andrzej Hajda <a.hajda@samsung.com>
> > Cc: Archit Taneja <architt@codeaurora.org>
> > ---
> > 
> > Changes v1->v2:
> > 	- Removed call to connector->mode_valid (Ville, Daniel)
> > 	- Change function name (Ville)
> > 	- Use for_each_new_connector_in_state (Ville)
> > 	- Do not validate if connector and mode didn't change (Ville)
> > 	- Use new helpers to call mode_valid
> > 
> >   drivers/gpu/drm/drm_atomic_helper.c | 75 +++++++++++++++++++++++++++++++++++--
> >   1 file changed, 72 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> > index 8be9719..19d0ea1 100644
> > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > @@ -452,6 +452,69 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
> >   	return 0;
> >   }
> > +static enum drm_mode_status mode_valid_path(struct drm_connector *connector,
> > +					    struct drm_encoder *encoder,
> > +					    struct drm_crtc *crtc,
> > +					    struct drm_display_mode *mode)
> > +{
> > +	enum drm_mode_status ret;
> > +
> > +	ret = drm_encoder_mode_valid(encoder, mode);
> > +	if (ret != MODE_OK) {
> > +		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] mode_valid() failed\n",
> > +				encoder->base.id, encoder->name);
> > +		return ret;
> > +	}
> > +
> > +	ret = drm_bridge_mode_valid(encoder->bridge, mode);
> > +	if (ret != MODE_OK) {
> > +		DRM_DEBUG_ATOMIC("[BRIDGE] mode_valid() failed\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = drm_crtc_mode_valid(crtc, mode);
> > +	if (ret != MODE_OK) {
> > +		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode_valid() failed\n",
> > +				crtc->base.id, crtc->name);
> > +		return ret;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static int
> > +mode_valid(struct drm_atomic_state *state)
> > +{
> > +	struct drm_connector_state *conn_state;
> > +	struct drm_connector *connector;
> > +	int i;
> > +
> > +	for_each_new_connector_in_state(state, connector, conn_state, i) {
> > +		struct drm_encoder *encoder = conn_state->best_encoder;
> > +		struct drm_crtc *crtc = conn_state->crtc;
> > +		struct drm_crtc_state *crtc_state;
> > +		enum drm_mode_status mode_status;
> > +		struct drm_display_mode *mode;
> > +
> > +		if (!crtc || !encoder)
> > +			continue;
> > +
> > +		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> > +		if (!crtc_state)
> > +			continue;
> > +		if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
> > +			continue;
> > +
> > +		mode = &crtc_state->mode;
> > +
> > +		mode_status = mode_valid_path(connector, encoder, crtc, mode);
> > +		if (mode_status != MODE_OK)
> > +			return -EINVAL;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >   /**
> >    * drm_atomic_helper_check_modeset - validate state object for modeset changes
> >    * @dev: DRM device
> > @@ -466,13 +529,15 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
> >    * 2. &drm_connector_helper_funcs.atomic_check to validate the connector state.
> >    * 3. If it's determined a modeset is needed then all connectors on the affected crtc
> >    *    crtc are added and &drm_connector_helper_funcs.atomic_check is run on them.
> > - * 4. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> > - * 5. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
> > + * 4. &drm_encoder_helper_funcs.mode_valid, &drm_bridge_funcs.mode_valid and
> > + *    &drm_crtc_helper_funcs.mode_valid are called on the affected components.
> > + * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> > + * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
> >    *    This function is only called when the encoder will be part of a configured crtc,
> >    *    it must not be used for implementing connector property validation.
> >    *    If this function is NULL, &drm_atomic_encoder_helper_funcs.mode_fixup is called
> >    *    instead.
> > - * 6. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with crtc constraints.
> > + * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with crtc constraints.
> >    *
> >    * &drm_crtc_state.mode_changed is set when the input mode is changed.
> >    * &drm_crtc_state.connectors_changed is set when a connector is added or
> > @@ -617,6 +682,10 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
> >   			return ret;
> >   	}
> > +	ret = mode_valid(state);
> > +	if (ret)
> > +		return ret;
> > +
> 
> Since we've ensured that the modes won't fail, can mode_fixup() and
> the mode_fixup() ops for crtc/bridge/encoders be assured to not fail
> too? This is assuming that all drivers have moved to using the new
> mode_valid() ops correctly.

The entire point of re-checking is that userspace can create its own modes
and submit them to the kernel, bypassing the current
connector->mode_valid() check. I think almost all drivers get this wrong
unfortunately :(
-Daniel
Laurent Pinchart May 12, 2017, 9:53 a.m. UTC | #3
Hi Daniel,

On Wednesday 10 May 2017 19:55:56 Daniel Vetter wrote:
> On Wed, May 10, 2017 at 09:38:00PM +0530, Archit Taneja wrote:
> > On 5/9/2017 10:30 PM, Jose Abreu wrote:
> > > This patches makes use of the new mode_valid() callbacks introduced
> > > previously to validate the full video pipeline when modesetting.
> > > 
> > > This calls the connector->mode_valid(), encoder->mode_valid(),
> > > bridge->mode_valid() and crtc->mode_valid() so that we can
> > > make sure that the mode will be accepted in every components.
> > > 
> > > Signed-off-by: Jose Abreu <joabreu@synopsys.com>
> > > Cc: Carlos Palminha <palminha@synopsys.com>
> > > Cc: Alexey Brodkin <abrodkin@synopsys.com>
> > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > Cc: Dave Airlie <airlied@linux.ie>
> > > Cc: Andrzej Hajda <a.hajda@samsung.com>
> > > Cc: Archit Taneja <architt@codeaurora.org>
> > > ---
> > > 
> > > Changes v1->v2:
> > > 	- Removed call to connector->mode_valid (Ville, Daniel)
> > > 	- Change function name (Ville)
> > > 	- Use for_each_new_connector_in_state (Ville)
> > > 	- Do not validate if connector and mode didn't change (Ville)
> > > 	- Use new helpers to call mode_valid
> > > 	
> > >   drivers/gpu/drm/drm_atomic_helper.c | 75 +++++++++++++++++++++++++++--
> > >   1 file changed, 72 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c
> > > b/drivers/gpu/drm/drm_atomic_helper.c index 8be9719..19d0ea1 100644
> > > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > > @@ -452,6 +452,69 @@ static int handle_conflicting_encoders(struct
> > > drm_atomic_state *state,
> > >   	return 0;
> > >   }
> > > 
> > > +static enum drm_mode_status mode_valid_path(struct drm_connector
> > > *connector,
> > > +					    struct drm_encoder *encoder,
> > > +					    struct drm_crtc *crtc,
> > > +					    struct drm_display_mode *mode)
> > > +{
> > > +	enum drm_mode_status ret;
> > > +
> > > +	ret = drm_encoder_mode_valid(encoder, mode);
> > > +	if (ret != MODE_OK) {
> > > +		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] mode_valid() failed\n",
> > > +				encoder->base.id, encoder->name);
> > > +		return ret;
> > > +	}
> > > +
> > > +	ret = drm_bridge_mode_valid(encoder->bridge, mode);
> > > +	if (ret != MODE_OK) {
> > > +		DRM_DEBUG_ATOMIC("[BRIDGE] mode_valid() failed\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	ret = drm_crtc_mode_valid(crtc, mode);
> > > +	if (ret != MODE_OK) {
> > > +		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode_valid() failed\n",
> > > +				crtc->base.id, crtc->name);
> > > +		return ret;
> > > +	}
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static int
> > > +mode_valid(struct drm_atomic_state *state)
> > > +{
> > > +	struct drm_connector_state *conn_state;
> > > +	struct drm_connector *connector;
> > > +	int i;
> > > +
> > > +	for_each_new_connector_in_state(state, connector, conn_state, i) {
> > > +		struct drm_encoder *encoder = conn_state->best_encoder;
> > > +		struct drm_crtc *crtc = conn_state->crtc;
> > > +		struct drm_crtc_state *crtc_state;
> > > +		enum drm_mode_status mode_status;
> > > +		struct drm_display_mode *mode;
> > > +
> > > +		if (!crtc || !encoder)
> > > +			continue;
> > > +
> > > +		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> > > +		if (!crtc_state)
> > > +			continue;
> > > +		if (!crtc_state->mode_changed && !crtc_state
> > > ->connectors_changed)
> > > +			continue;
> > > +
> > > +		mode = &crtc_state->mode;
> > > +
> > > +		mode_status = mode_valid_path(connector, encoder, crtc, mode);
> > > +		if (mode_status != MODE_OK)
> > > +			return -EINVAL;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > >   /**
> > >    * drm_atomic_helper_check_modeset - validate state object for modeset
> > >    changes * @dev: DRM device
> > > @@ -466,13 +529,15 @@ static int handle_conflicting_encoders(struct
> > > drm_atomic_state *state,
> > >   * 2. &drm_connector_helper_funcs.atomic_check to validate the
> > >   connector state.
> > >   * 3. If it's determined a modeset is needed then all connectors on the
> > >   affected crtc
> > >   *    crtc are added and &drm_connector_helper_funcs.atomic_check is
> > >   run on them.
> > > - * 4. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> > > - * 5. &drm_encoder_helper_funcs.atomic_check is called to validate any
> > > encoder state.
> > > + * 4. &drm_encoder_helper_funcs.mode_valid,
> > > &drm_bridge_funcs.mode_valid and
> > > + *    &drm_crtc_helper_funcs.mode_valid are called on the affected
> > > components.
> > > + * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> > > + * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any
> > > encoder state.
> > >   *    This function is only called when the encoder will be part of a
> > >   configured crtc,
> > >   *    it must not be used for implementing connector property
> > >   validation.
> > >   *    If this function is NULL,
> > >   &drm_atomic_encoder_helper_funcs.mode_fixup is called
> > >   *    instead.
> > > - * 6. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the
> > > mode with crtc constraints.
> > > + * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the
> > > mode with crtc constraints.
> > >    *
> > >    * &drm_crtc_state.mode_changed is set when the input mode is changed.
> > >    * &drm_crtc_state.connectors_changed is set when a connector is added
> > >    or
> > > 
> > > @@ -617,6 +682,10 @@ static int handle_conflicting_encoders(struct
> > > drm_atomic_state *state,
> > >   			return ret;
> > >   	}
> > > 
> > > +	ret = mode_valid(state);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > 
> > Since we've ensured that the modes won't fail, can mode_fixup() and
> > the mode_fixup() ops for crtc/bridge/encoders be assured to not fail
> > too? This is assuming that all drivers have moved to using the new
> > mode_valid() ops correctly.
> 
> The entire point of re-checking is that userspace can create its own modes
> and submit them to the kernel, bypassing the current
> connector->mode_valid() check. I think almost all drivers get this wrong
> unfortunately :(

How about documenting the expected driver behaviour in details ? I won't 
volunteer as I have to confess it's not clear to me what we expect from 
drivers.
Daniel Vetter May 15, 2017, 6:50 a.m. UTC | #4
On Fri, May 12, 2017 at 12:53:56PM +0300, Laurent Pinchart wrote:
> Hi Daniel,
> 
> On Wednesday 10 May 2017 19:55:56 Daniel Vetter wrote:
> > On Wed, May 10, 2017 at 09:38:00PM +0530, Archit Taneja wrote:
> > > On 5/9/2017 10:30 PM, Jose Abreu wrote:
> > > > This patches makes use of the new mode_valid() callbacks introduced
> > > > previously to validate the full video pipeline when modesetting.
> > > > 
> > > > This calls the connector->mode_valid(), encoder->mode_valid(),
> > > > bridge->mode_valid() and crtc->mode_valid() so that we can
> > > > make sure that the mode will be accepted in every components.
> > > > 
> > > > Signed-off-by: Jose Abreu <joabreu@synopsys.com>
> > > > Cc: Carlos Palminha <palminha@synopsys.com>
> > > > Cc: Alexey Brodkin <abrodkin@synopsys.com>
> > > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > > Cc: Dave Airlie <airlied@linux.ie>
> > > > Cc: Andrzej Hajda <a.hajda@samsung.com>
> > > > Cc: Archit Taneja <architt@codeaurora.org>
> > > > ---
> > > > 
> > > > Changes v1->v2:
> > > > 	- Removed call to connector->mode_valid (Ville, Daniel)
> > > > 	- Change function name (Ville)
> > > > 	- Use for_each_new_connector_in_state (Ville)
> > > > 	- Do not validate if connector and mode didn't change (Ville)
> > > > 	- Use new helpers to call mode_valid
> > > > 	
> > > >   drivers/gpu/drm/drm_atomic_helper.c | 75 +++++++++++++++++++++++++++--
> > > >   1 file changed, 72 insertions(+), 3 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c
> > > > b/drivers/gpu/drm/drm_atomic_helper.c index 8be9719..19d0ea1 100644
> > > > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > > > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > > > @@ -452,6 +452,69 @@ static int handle_conflicting_encoders(struct
> > > > drm_atomic_state *state,
> > > >   	return 0;
> > > >   }
> > > > 
> > > > +static enum drm_mode_status mode_valid_path(struct drm_connector
> > > > *connector,
> > > > +					    struct drm_encoder *encoder,
> > > > +					    struct drm_crtc *crtc,
> > > > +					    struct drm_display_mode *mode)
> > > > +{
> > > > +	enum drm_mode_status ret;
> > > > +
> > > > +	ret = drm_encoder_mode_valid(encoder, mode);
> > > > +	if (ret != MODE_OK) {
> > > > +		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] mode_valid() failed\n",
> > > > +				encoder->base.id, encoder->name);
> > > > +		return ret;
> > > > +	}
> > > > +
> > > > +	ret = drm_bridge_mode_valid(encoder->bridge, mode);
> > > > +	if (ret != MODE_OK) {
> > > > +		DRM_DEBUG_ATOMIC("[BRIDGE] mode_valid() failed\n");
> > > > +		return ret;
> > > > +	}
> > > > +
> > > > +	ret = drm_crtc_mode_valid(crtc, mode);
> > > > +	if (ret != MODE_OK) {
> > > > +		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode_valid() failed\n",
> > > > +				crtc->base.id, crtc->name);
> > > > +		return ret;
> > > > +	}
> > > > +
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +static int
> > > > +mode_valid(struct drm_atomic_state *state)
> > > > +{
> > > > +	struct drm_connector_state *conn_state;
> > > > +	struct drm_connector *connector;
> > > > +	int i;
> > > > +
> > > > +	for_each_new_connector_in_state(state, connector, conn_state, i) {
> > > > +		struct drm_encoder *encoder = conn_state->best_encoder;
> > > > +		struct drm_crtc *crtc = conn_state->crtc;
> > > > +		struct drm_crtc_state *crtc_state;
> > > > +		enum drm_mode_status mode_status;
> > > > +		struct drm_display_mode *mode;
> > > > +
> > > > +		if (!crtc || !encoder)
> > > > +			continue;
> > > > +
> > > > +		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> > > > +		if (!crtc_state)
> > > > +			continue;
> > > > +		if (!crtc_state->mode_changed && !crtc_state
> > > > ->connectors_changed)
> > > > +			continue;
> > > > +
> > > > +		mode = &crtc_state->mode;
> > > > +
> > > > +		mode_status = mode_valid_path(connector, encoder, crtc, mode);
> > > > +		if (mode_status != MODE_OK)
> > > > +			return -EINVAL;
> > > > +	}
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > >   /**
> > > >    * drm_atomic_helper_check_modeset - validate state object for modeset
> > > >    changes * @dev: DRM device
> > > > @@ -466,13 +529,15 @@ static int handle_conflicting_encoders(struct
> > > > drm_atomic_state *state,
> > > >   * 2. &drm_connector_helper_funcs.atomic_check to validate the
> > > >   connector state.
> > > >   * 3. If it's determined a modeset is needed then all connectors on the
> > > >   affected crtc
> > > >   *    crtc are added and &drm_connector_helper_funcs.atomic_check is
> > > >   run on them.
> > > > - * 4. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> > > > - * 5. &drm_encoder_helper_funcs.atomic_check is called to validate any
> > > > encoder state.
> > > > + * 4. &drm_encoder_helper_funcs.mode_valid,
> > > > &drm_bridge_funcs.mode_valid and
> > > > + *    &drm_crtc_helper_funcs.mode_valid are called on the affected
> > > > components.
> > > > + * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
> > > > + * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any
> > > > encoder state.
> > > >   *    This function is only called when the encoder will be part of a
> > > >   configured crtc,
> > > >   *    it must not be used for implementing connector property
> > > >   validation.
> > > >   *    If this function is NULL,
> > > >   &drm_atomic_encoder_helper_funcs.mode_fixup is called
> > > >   *    instead.
> > > > - * 6. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the
> > > > mode with crtc constraints.
> > > > + * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the
> > > > mode with crtc constraints.
> > > >    *
> > > >    * &drm_crtc_state.mode_changed is set when the input mode is changed.
> > > >    * &drm_crtc_state.connectors_changed is set when a connector is added
> > > >    or
> > > > 
> > > > @@ -617,6 +682,10 @@ static int handle_conflicting_encoders(struct
> > > > drm_atomic_state *state,
> > > >   			return ret;
> > > >   	}
> > > > 
> > > > +	ret = mode_valid(state);
> > > > +	if (ret)
> > > > +		return ret;
> > > > +
> > > 
> > > Since we've ensured that the modes won't fail, can mode_fixup() and
> > > the mode_fixup() ops for crtc/bridge/encoders be assured to not fail
> > > too? This is assuming that all drivers have moved to using the new
> > > mode_valid() ops correctly.
> > 
> > The entire point of re-checking is that userspace can create its own modes
> > and submit them to the kernel, bypassing the current
> > connector->mode_valid() check. I think almost all drivers get this wrong
> > unfortunately :(
> 
> How about documenting the expected driver behaviour in details ? I won't 
> volunteer as I have to confess it's not clear to me what we expect from 
> drivers.

It already is? Or where exactly is it lacking in the docs?
-Daniel
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 8be9719..19d0ea1 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -452,6 +452,69 @@  static int handle_conflicting_encoders(struct drm_atomic_state *state,
 	return 0;
 }
 
+static enum drm_mode_status mode_valid_path(struct drm_connector *connector,
+					    struct drm_encoder *encoder,
+					    struct drm_crtc *crtc,
+					    struct drm_display_mode *mode)
+{
+	enum drm_mode_status ret;
+
+	ret = drm_encoder_mode_valid(encoder, mode);
+	if (ret != MODE_OK) {
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] mode_valid() failed\n",
+				encoder->base.id, encoder->name);
+		return ret;
+	}
+
+	ret = drm_bridge_mode_valid(encoder->bridge, mode);
+	if (ret != MODE_OK) {
+		DRM_DEBUG_ATOMIC("[BRIDGE] mode_valid() failed\n");
+		return ret;
+	}
+
+	ret = drm_crtc_mode_valid(crtc, mode);
+	if (ret != MODE_OK) {
+		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode_valid() failed\n",
+				crtc->base.id, crtc->name);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int
+mode_valid(struct drm_atomic_state *state)
+{
+	struct drm_connector_state *conn_state;
+	struct drm_connector *connector;
+	int i;
+
+	for_each_new_connector_in_state(state, connector, conn_state, i) {
+		struct drm_encoder *encoder = conn_state->best_encoder;
+		struct drm_crtc *crtc = conn_state->crtc;
+		struct drm_crtc_state *crtc_state;
+		enum drm_mode_status mode_status;
+		struct drm_display_mode *mode;
+
+		if (!crtc || !encoder)
+			continue;
+
+		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+		if (!crtc_state)
+			continue;
+		if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
+			continue;
+
+		mode = &crtc_state->mode;
+
+		mode_status = mode_valid_path(connector, encoder, crtc, mode);
+		if (mode_status != MODE_OK)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 /**
  * drm_atomic_helper_check_modeset - validate state object for modeset changes
  * @dev: DRM device
@@ -466,13 +529,15 @@  static int handle_conflicting_encoders(struct drm_atomic_state *state,
  * 2. &drm_connector_helper_funcs.atomic_check to validate the connector state.
  * 3. If it's determined a modeset is needed then all connectors on the affected crtc
  *    crtc are added and &drm_connector_helper_funcs.atomic_check is run on them.
- * 4. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
- * 5. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
+ * 4. &drm_encoder_helper_funcs.mode_valid, &drm_bridge_funcs.mode_valid and
+ *    &drm_crtc_helper_funcs.mode_valid are called on the affected components.
+ * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
+ * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
  *    This function is only called when the encoder will be part of a configured crtc,
  *    it must not be used for implementing connector property validation.
  *    If this function is NULL, &drm_atomic_encoder_helper_funcs.mode_fixup is called
  *    instead.
- * 6. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with crtc constraints.
+ * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with crtc constraints.
  *
  * &drm_crtc_state.mode_changed is set when the input mode is changed.
  * &drm_crtc_state.connectors_changed is set when a connector is added or
@@ -617,6 +682,10 @@  static int handle_conflicting_encoders(struct drm_atomic_state *state,
 			return ret;
 	}
 
+	ret = mode_valid(state);
+	if (ret)
+		return ret;
+
 	return mode_fixup(state);
 }
 EXPORT_SYMBOL(drm_atomic_helper_check_modeset);