Hi Rob and Abhinav,
On Mon, Apr 04, 2022 at 11:43:37AM -0700, Rob Clark wrote:
> On Fri, Apr 1, 2022 at 8:38 AM Laurent Pinchart wrote:
> > On Thu, Mar 31, 2022 at 05:12:13PM -0700, Abhinav Kumar wrote:
> > > For some vendor driver implementations, display hardware can
> > > be shared between the encoder used for writeback and the physical
> > > display.
> > >
> > > In addition resources such as clocks and interrupts can
> > > also be shared between writeback and the real encoder.
> > >
> > > To accommodate such vendor drivers and hardware, allow
> > > real encoder to be passed for drm_writeback_connector.
> > >
> > > changes in v6:
> > > - assign the encoder inside
> > > drm_writeback_connector_init_with_encoder() for
> > > better readability
> > > - improve some documentation for internal encoder
> > >
> > > Co-developed-by: Kandpal Suraj <suraj.kandpal@xxxxxxxxx>
> > > Signed-off-by: Kandpal Suraj <suraj.kandpal@xxxxxxxxx>
> > > Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/drm_writeback.c | 18 ++++++++++++------
> > > drivers/gpu/drm/vc4/vc4_txp.c | 14 ++++++++------
> > > include/drm/drm_writeback.h | 21 +++++++++++++++++++--
> >
> > Please split this in two patches, one for the DRM core and one for the
> > VC4 driver. This applies to most patches as a general rule, with the
> > main exception being API refactoring that requires changing the
> > implementation and all its users in a single patch.
>
> But this *is* API refactoring ;-)
Partly at least :-) Looking at the API change itself, wouldn't we
minimize the extra changes to vc4 if we moved this patch before 3/4 ?
> > > 3 files changed, 39 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> > > index 797223c..7f72109 100644
> > > --- a/drivers/gpu/drm/drm_writeback.c
> > > +++ b/drivers/gpu/drm/drm_writeback.c
> > > @@ -179,21 +179,21 @@ int drm_writeback_connector_init(struct drm_device *dev,
> > > {
> > > int ret = 0;
> > >
> > > - drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
> > > + drm_encoder_helper_add(&wb_connector->internal_encoder, enc_helper_funcs);
> > >
> > > - wb_connector->encoder.possible_crtcs = possible_crtcs;
> > > + wb_connector->internal_encoder.possible_crtcs = possible_crtcs;
> > >
> > > - ret = drm_encoder_init(dev, &wb_connector->encoder,
> > > + ret = drm_encoder_init(dev, &wb_connector->internal_encoder,
> > > &drm_writeback_encoder_funcs,
> > > DRM_MODE_ENCODER_VIRTUAL, NULL);
> > > if (ret)
> > > return ret;
> > >
> > > - ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,
> > > - con_funcs, formats, n_formats);
> > > + ret = drm_writeback_connector_init_with_encoder(dev, wb_connector,
> > > + &wb_connector->internal_encoder, con_funcs, formats, n_formats);
> > >
> > > if (ret)
> > > - drm_encoder_cleanup(&wb_connector->encoder);
> > > + drm_encoder_cleanup(&wb_connector->internal_encoder);
> > >
> > > return ret;
> > > }
> > > @@ -238,6 +238,12 @@ int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
> > > struct drm_mode_config *config = &dev->mode_config;
> > > int ret = create_writeback_properties(dev);
> > >
> > > + /*
> > > + * Assign the encoder passed to this API to the wb_connector's encoder.
> > > + * For drm_writeback_connector_init(), this shall be the internal_encoder
> > > + */
> > > + wb_connector->encoder = enc;
> > > +
> > > if (ret != 0)
> > > return ret;
> > >
> > > diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
> > > index 5e53f02..a9b4f83 100644
> > > --- a/drivers/gpu/drm/vc4/vc4_txp.c
> > > +++ b/drivers/gpu/drm/vc4/vc4_txp.c
> > > @@ -151,6 +151,8 @@ struct vc4_txp {
> > >
> > > struct platform_device *pdev;
> > >
> > > + struct drm_encoder drm_enc;
> > > +
> > > struct drm_writeback_connector connector;
> > >
> > > void __iomem *regs;
> > > @@ -159,7 +161,7 @@ struct vc4_txp {
> > >
> > > static inline struct vc4_txp *encoder_to_vc4_txp(struct drm_encoder *encoder)
> > > {
> > > - return container_of(encoder, struct vc4_txp, connector.encoder);
> > > + return container_of(encoder, struct vc4_txp, drm_enc);
> > > }
> > >
> > > static inline struct vc4_txp *connector_to_vc4_txp(struct drm_connector *conn)
> > > @@ -499,9 +501,9 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
> > >
> > > wb_conn = &txp->connector;
> > >
> > > - drm_encoder_helper_add(&wb_conn->encoder, &vc4_txp_encoder_helper_funcs);
> > > + drm_encoder_helper_add(&txp->drm_enc, &vc4_txp_encoder_helper_funcs);
> > >
> > > - ret = drm_encoder_init(drm, &wb_conn->encoder,
> > > + ret = drm_encoder_init(drm, &txp->drm_enc,
> > > &vc4_txp_encoder_funcs,
> > > DRM_MODE_ENCODER_VIRTUAL, NULL);
> > >
> > > @@ -511,10 +513,10 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
> > > drm_connector_helper_add(&wb_conn->base,
> > > &vc4_txp_connector_helper_funcs);
> > >
> > > - ret = drm_writeback_connector_init_with_encoder(drm, wb_conn, &wb_conn->encoder,
> > > + ret = drm_writeback_connector_init_with_encoder(drm, wb_conn, &txp->drm_enc,
> > > &vc4_txp_connector_funcs, drm_fmts, ARRAY_SIZE(drm_fmts));
> > > if (ret) {
> > > - drm_encoder_cleanup(&wb_conn->encoder);
> > > + drm_encoder_cleanup(&txp->drm_enc);
> > > return ret;
> > > }
> > >
> > > @@ -523,7 +525,7 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
> > > if (ret)
> > > return ret;
> > >
> > > - encoder = &txp->connector.encoder;
> > > + encoder = txp->connector.encoder;
> > > encoder->possible_crtcs = drm_crtc_mask(crtc);
> > >
> > > ret = devm_request_irq(dev, irq, vc4_txp_interrupt, 0,
> > > diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
> > > index 4795024..3f5c330 100644
> > > --- a/include/drm/drm_writeback.h
> > > +++ b/include/drm/drm_writeback.h
> > > @@ -25,15 +25,32 @@ struct drm_writeback_connector {
> > > struct drm_connector base;
> > >
> > > /**
> > > - * @encoder: Internal encoder used by the connector to fulfill
> > > + * @encoder: handle to drm_encoder used by the connector to fulfill
> > > * the DRM framework requirements. The users of the
> > > * @drm_writeback_connector control the behaviour of the @encoder
> > > * by passing the @enc_funcs parameter to drm_writeback_connector_init()
> > > * function.
> > > + *
> > > + * For some vendor drivers, the hardware resources are shared between
> > > + * writeback encoder and rest of the display pipeline.
> > > + * To accommodate such cases, encoder is a handle to the real encoder
> > > + * hardware.
> > > + *
> > > + * For current existing writeback users, this shall continue to be the
> > > + * embedded encoder for the writeback connector.
> > > */
> > > - struct drm_encoder encoder;
> > > + struct drm_encoder *encoder;
> > >
> > > /**
> > > + * @internal_encoder: internal encoder used by writeback when
> > > + * drm_writeback_connector_init() is used.
> > > + * @encoder will be assigned to this for those cases
> > > + *
> > > + * This will be unused when drm_writeback_connector_init_with_encoder()
> > > + * is used.
> > > + */
> > > + struct drm_encoder internal_encoder;
> > > + /**
> > > * @pixel_formats_blob_ptr:
> > > *
> > > * DRM blob property data for the pixel formats list on writeback
--
Regards,
Laurent Pinchart
