Hi Abhinav,
On Tue, Apr 05, 2022 at 09:53:57AM -0700, Abhinav Kumar wrote:
> On 4/5/2022 9:47 AM, Laurent Pinchart wrote:
> > 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 ?
>
> I can move all the changes done in vc4 except below part to the change
> 3/4 itself because that way I can show usage of vc4->drm_enc with the
> new API. Let me know if that works.
What I meant is moving the API refactoring from 4/4 before the current
3/4, with minimal changes to vc4 there (only to avoid introducing a
bisection breakge), and then move most of the vc4 changes from this
patch to the current 3/4 (which will become 4/4). If that's what you
meant too, it sounds good to me.
> The only part which will remain is the below one:
>
> @@ -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);
>
> Since i dont know vc4 driver very well, I was not sure of a good way to
> decouple this dependency.
>
> Let me know if that works.
>
> >>>> 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
