> -----Original Message-----
> From: John Harrison <[email protected]>
> Sent: 18 July 2026 01:10
> To: Kandpal, Suraj <[email protected]>; [email protected];
> [email protected]; [email protected]; amd-
> [email protected]; [email protected]; intel-
> [email protected]; [email protected]
> Cc: Shankar, Uma <[email protected]>; Murthy, Arun R
> <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; Liviu Dudau <[email protected]>
> Subject: Re: [PATCH v6 1/7] drm: writeback: Refactor drm_writeback_connector
> structure
>
> On 7/13/26 21:27, Suraj Kandpal wrote:
> > Some drivers cannot work with the current design where the connector
> > is embedded within the drm_writeback_connector such as Intel and some
> > drivers that can get it working end up adding a lot of checks all
> > around the code to check if it's a writeback conenctor or not, this is
> > due to the limitation of inheritance in C.
> > To solve this move the drm_writeback_connector within the
> > drm_connector and remove the drm_connector base which was in
> > drm_writeback_connector. Make this drm_writeback_connector a union
> > with hdmi connector to save memory and since a connector can never be
> > both writeback and hdmi it should serve us well.
> > Do all other required modifications that come with these changes along
> > with addition of new function which returns the drm_connector when
> > drm_writeback_connector is present.
> > Modify drivers using the drm_writeback_connector to allow them to use
> > this connector without breaking them.
> > The drivers modified here are amd, komeda, mali, vc4, vkms, rcar_du,
> > msm
> >
> > Signed-off-by: Suraj Kandpal <[email protected]>
> > Reviewed-by: Liviu Dudau <[email protected]>
> > Reviewed-by: Louis Chauvet <[email protected]>
> > Reviewed-by: John Harrison <[email protected]>
> > ---
> > v5 -> v6:
> > - Rebase on latest kernel
> >
> > v4 -> v5:
> > - Remove more unnecessary wrapping of drm_writeback_to_connector()
> > (John)
> >
> > v3 -> v4:
> > - Use drm_writeback_to_connector() wherever possible (John)
> > - Do not wrap line where not needed (John)
> >
> > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
> > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 2 +-
> > .../display/amdgpu_dm/amdgpu_dm_connector.c | 4 +-
> > .../drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c | 8 +--
> > .../gpu/drm/arm/display/komeda/komeda_crtc.c | 6 +-
> > .../gpu/drm/arm/display/komeda/komeda_kms.h | 6 +-
> > .../arm/display/komeda/komeda_wb_connector.c | 8 +--
> > drivers/gpu/drm/arm/malidp_crtc.c | 2 +-
> > drivers/gpu/drm/arm/malidp_drv.h | 2 +-
> > drivers/gpu/drm/arm/malidp_hw.c | 6 +-
> > drivers/gpu/drm/arm/malidp_mw.c | 8 +--
> > drivers/gpu/drm/drm_atomic_uapi.c | 2 +-
> > drivers/gpu/drm/drm_writeback.c | 28 ++++----
> > .../drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 3 +-
> > drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 14 ++--
> > drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h | 4 +-
> > .../gpu/drm/renesas/rcar-du/rcar_du_crtc.h | 6 +-
> > .../drm/renesas/rcar-du/rcar_du_writeback.c | 16 +++--
> > drivers/gpu/drm/vc4/vc4_txp.c | 12 ++--
> > drivers/gpu/drm/vkms/vkms_composer.c | 2 +-
> > drivers/gpu/drm/vkms/vkms_drv.h | 2 +-
> > drivers/gpu/drm/vkms/vkms_writeback.c | 13 ++--
> > include/drm/drm_connector.h | 69 +++++++++++++++++--
> > include/drm/drm_writeback.h | 66 +-----------------
> > 24 files changed, 150 insertions(+), 141 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > index 1726eb6a3c63..427a8a52d256 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -4885,7 +4885,7 @@ static void dm_set_writeback(struct
> amdgpu_display_manager *dm,
> > struct drm_connector *connector,
> > struct drm_connector_state *new_con_state)
> > {
> > - struct drm_writeback_connector *wb_conn =
> drm_connector_to_writeback(connector);
> > + struct drm_writeback_connector *wb_conn = &connector->writeback;
> > struct amdgpu_device *adev = dm->adev;
> > struct amdgpu_crtc *acrtc;
> > struct dc_writeback_info *wb_info;
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> > index 91affbdb2d6c..a1faf9f3670e 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> > @@ -894,7 +894,7 @@ static inline void amdgpu_dm_set_mst_status(uint8_t
> *status,
> > #define to_amdgpu_dm_connector(x) container_of(x, struct
> > amdgpu_dm_connector, base)
> >
> > struct amdgpu_dm_wb_connector {
> > - struct drm_writeback_connector base;
> > + struct drm_connector base;
> > struct dc_link *link;
> > };
> >
> > diff --git
> > a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> > index 88f938a8f24f..d48d764eae63 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> > @@ -1368,11 +1368,9 @@ create_stream_for_sink(struct drm_connector
> *connector,
> > aconnector = to_amdgpu_dm_connector(connector);
> > link = aconnector->dc_link;
> > } else {
> > - struct drm_writeback_connector *wbcon = NULL;
> > struct amdgpu_dm_wb_connector *dm_wbcon = NULL;
> >
> > - wbcon = drm_connector_to_writeback(connector);
> > - dm_wbcon = to_amdgpu_dm_wb_connector(wbcon);
> > + dm_wbcon = to_amdgpu_dm_wb_connector(connector);
> > link = dm_wbcon->link;
> > }
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
> > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
> > index 3ee31634549e..18ef4ce73b46 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
> > @@ -205,9 +205,9 @@ int amdgpu_dm_wb_connector_init(struct
> > amdgpu_display_manager *dm,
> >
> > wbcon->link = link;
> >
> > - drm_connector_helper_add(&wbcon->base.base,
> &amdgpu_dm_wb_conn_helper_funcs);
> > + drm_connector_helper_add(&wbcon->base,
> > +&amdgpu_dm_wb_conn_helper_funcs);
> >
> > - res = drmm_writeback_connector_init(&dm->adev->ddev, &wbcon-
> >base,
> > + res = drmm_writeback_connector_init(&dm->adev->ddev,
> > +&wbcon->base.writeback,
> >
> &amdgpu_dm_wb_connector_funcs,
> > encoder,
> > amdgpu_dm_wb_formats,
> > @@ -219,8 +219,8 @@ int amdgpu_dm_wb_connector_init(struct
> amdgpu_display_manager *dm,
> > * Some of the properties below require access to state, like bpc.
> > * Allocate some default initial connector state with our reset helper.
> > */
> > - if (wbcon->base.base.funcs->reset)
> > - wbcon->base.base.funcs->reset(&wbcon->base.base);
> > + if (wbcon->base.funcs->reset)
> > + wbcon->base.funcs->reset(&wbcon->base);
> >
> > return 0;
> > }
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> > b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> > index e8cb782a6f8e..6611920c45fb 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> > @@ -213,7 +213,7 @@ void komeda_crtc_handle_event(struct komeda_crtc
> *kcrtc,
> > struct komeda_wb_connector *wb_conn = kcrtc->wb_conn;
> >
> > if (wb_conn)
> > - drm_writeback_signal_completion(&wb_conn->base,
> 0);
> > + drm_writeback_signal_completion(&wb_conn-
> >base.writeback, 0);
> > else
> > drm_warn(drm, "CRTC[%d]: EOW happen but no
> wb_connector.\n",
> > drm_crtc_index(&kcrtc->base));
> > @@ -269,9 +269,9 @@ komeda_crtc_do_flush(struct drm_crtc *crtc,
> > if (slave && has_bit(slave->id, kcrtc_st->affected_pipes))
> > komeda_pipeline_update(slave, old->state);
> >
> > - conn_st = wb_conn ? wb_conn->base.base.state : NULL;
> > + conn_st = wb_conn ? wb_conn->base.state : NULL;
> > if (conn_st && conn_st->writeback_job)
> > - drm_writeback_queue_job(&wb_conn->base, conn_st);
> > + drm_writeback_queue_job(&wb_conn->base.writeback,
> conn_st);
> >
> > /* step 2: notify the HW to kickoff the update */
> > mdev->funcs->flush(mdev, master->id, kcrtc_st->active_pipes); diff
> > --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
> > b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
> > index 83e61c4080c2..9c34302782c0 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
> > @@ -53,8 +53,8 @@ struct komeda_plane_state {
> > * struct komeda_wb_connector
> > */
> > struct komeda_wb_connector {
> > - /** @base: &drm_writeback_connector */
> > - struct drm_writeback_connector base;
> > + /** @base: &drm_connector */
> > + struct drm_connector base;
> >
> > /** @wb_layer: represents associated writeback pipeline of komeda */
> > struct komeda_layer *wb_layer;
> > @@ -139,7 +139,7 @@ struct komeda_kms_dev {
> > static inline bool is_writeback_only(struct drm_crtc_state *st)
> > {
> > struct komeda_wb_connector *wb_conn = to_kcrtc(st->crtc)-
> >wb_conn;
> > - struct drm_connector *conn = wb_conn ? &wb_conn->base.base :
> NULL;
> > + struct drm_connector *conn = wb_conn ? &wb_conn->base : NULL;
> >
> > return conn && (st->connector_mask ==
> BIT(drm_connector_index(conn)));
> > }
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
> > b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
> > index c1bedbaa26f9..848ac37a76e4 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
> > @@ -53,7 +53,7 @@ komeda_wb_encoder_atomic_check(struct
> drm_encoder *encoder,
> > return -EINVAL;
> > }
> >
> > - wb_layer = to_kconn(to_wb_conn(conn_st->connector))->wb_layer;
> > + wb_layer = to_kconn(conn_st->connector)->wb_layer;
> >
> > /*
> > * No need for a full modested when the only connector changed is
> > the @@ -151,7 +151,7 @@ static int komeda_wb_connector_add(struct
> > komeda_kms_dev *kms,
> >
> > kwb_conn->wb_layer = kcrtc->master->wb_layer;
> >
> > - wb_conn = &kwb_conn->base;
> > + wb_conn = &kwb_conn->base.writeback;
> >
> > formats = komeda_get_layer_fourcc_list(&mdev->fmt_tbl,
> > kwb_conn->wb_layer->layer_type,
> @@ -183,9 +183,9 @@
> > static int komeda_wb_connector_add(struct komeda_kms_dev *kms,
> > return err;
> > }
> >
> > - drm_connector_helper_add(&wb_conn->base,
> &komeda_wb_conn_helper_funcs);
> > + drm_connector_helper_add(&kwb_conn->base,
> > +&komeda_wb_conn_helper_funcs);
> >
> > - info = &kwb_conn->base.base.display_info;
> > + info = &kwb_conn->base.display_info;
> > info->bpc = __fls(kcrtc->master->improc->supported_color_depths);
> > info->color_formats =
> > kcrtc->master->improc->supported_color_formats;
> >
> > diff --git a/drivers/gpu/drm/arm/malidp_crtc.c
> > b/drivers/gpu/drm/arm/malidp_crtc.c
> > index ebe8e1078777..4402c1de8c69 100644
> > --- a/drivers/gpu/drm/arm/malidp_crtc.c
> > +++ b/drivers/gpu/drm/arm/malidp_crtc.c
> > @@ -421,7 +421,7 @@ static int malidp_crtc_atomic_check(struct drm_crtc
> *crtc,
> > u32 new_mask = crtc_state->connector_mask;
> >
> > if ((old_mask ^ new_mask) ==
> > - (1 << drm_connector_index(&malidp->mw_connector.base)))
> > + (1 << drm_connector_index(&malidp->mw_connector)))
> > crtc_state->connectors_changed = false;
> > }
> >
> > diff --git a/drivers/gpu/drm/arm/malidp_drv.h
> > b/drivers/gpu/drm/arm/malidp_drv.h
> > index bc0387876dea..aa5599467d27 100644
> > --- a/drivers/gpu/drm/arm/malidp_drv.h
> > +++ b/drivers/gpu/drm/arm/malidp_drv.h
> > @@ -32,7 +32,7 @@ struct malidp_drm {
> > struct drm_device base;
> > struct malidp_hw_device *dev;
> > struct drm_crtc crtc;
> > - struct drm_writeback_connector mw_connector;
> > + struct drm_connector mw_connector;
> > wait_queue_head_t wq;
> > struct drm_pending_vblank_event *event;
> > atomic_t config_valid;
> > diff --git a/drivers/gpu/drm/arm/malidp_hw.c
> > b/drivers/gpu/drm/arm/malidp_hw.c index 9b845d3f34e1..5a7bd27d3718
> > 100644
> > --- a/drivers/gpu/drm/arm/malidp_hw.c
> > +++ b/drivers/gpu/drm/arm/malidp_hw.c
> > @@ -1315,15 +1315,15 @@ static irqreturn_t malidp_se_irq(int irq, void
> *arg)
> > if (status & se->vsync_irq) {
> > switch (hwdev->mw_state) {
> > case MW_ONESHOT:
> > - drm_writeback_signal_completion(&malidp-
> >mw_connector, 0);
> > + drm_writeback_signal_completion(&malidp-
> >mw_connector.writeback,
> > +0);
> > break;
> > case MW_STOP:
> > - drm_writeback_signal_completion(&malidp-
> >mw_connector, 0);
> > + drm_writeback_signal_completion(&malidp-
> >mw_connector.writeback,
> > +0);
> > /* disable writeback after stop */
> > hwdev->mw_state = MW_NOT_ENABLED;
> > break;
> > case MW_RESTART:
> > - drm_writeback_signal_completion(&malidp-
> >mw_connector, 0);
> > + drm_writeback_signal_completion(&malidp-
> >mw_connector.writeback,
> > +0);
> > fallthrough; /* to a new start */
> > case MW_START:
> > /* writeback started, need to emulate one-shot mode
> */ diff --git
> > a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c
> > index a4c6a00c0941..4c77a459c241 100644
> > --- a/drivers/gpu/drm/arm/malidp_mw.c
> > +++ b/drivers/gpu/drm/arm/malidp_mw.c
> > @@ -212,7 +212,7 @@ int malidp_mw_connector_init(struct drm_device
> *drm)
> > if (!malidp->dev->hw->enable_memwrite)
> > return 0;
> >
> > - drm_connector_helper_add(&malidp->mw_connector.base,
> > + drm_connector_helper_add(&malidp->mw_connector,
> > &malidp_mw_connector_helper_funcs);
> >
> > formats = get_writeback_formats(malidp, &n_formats); @@ -229,7
> > +229,7 @@ int malidp_mw_connector_init(struct drm_device *drm)
> >
> > encoder->possible_crtcs = drm_crtc_mask(&malidp->crtc);
> >
> > - ret = drmm_writeback_connector_init(drm, &malidp->mw_connector,
> > + ret = drmm_writeback_connector_init(drm,
> > +&malidp->mw_connector.writeback,
> > &malidp_mw_connector_funcs,
> > encoder,
> > formats, n_formats);
> > @@ -244,8 +244,8 @@ void malidp_mw_atomic_commit(struct drm_device
> *drm,
> > struct drm_atomic_commit *old_state)
> > {
> > struct malidp_drm *malidp = drm_to_malidp(drm);
> > - struct drm_writeback_connector *mw_conn = &malidp-
> >mw_connector;
> > - struct drm_connector_state *conn_state = mw_conn->base.state;
> > + struct drm_writeback_connector *mw_conn = &malidp-
> >mw_connector.writeback;
> > + struct drm_connector_state *conn_state = malidp-
> >mw_connector.state;
> > struct malidp_hw_device *hwdev = malidp->dev;
> > struct malidp_mw_connector_state *mw_state;
> >
> > diff --git a/drivers/gpu/drm/drm_atomic_uapi.c
> > b/drivers/gpu/drm/drm_atomic_uapi.c
> > index 1050dddadb17..a5c11832ff64 100644
> > --- a/drivers/gpu/drm/drm_atomic_uapi.c
> > +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> > @@ -1514,7 +1514,7 @@ static int prepare_signaling(struct drm_device
> *dev,
> > f[*num_fences].out_fence_ptr = fence_ptr;
> > *fence_state = f;
> >
> > - wb_conn = drm_connector_to_writeback(conn);
> > + wb_conn = &conn->writeback;
> > fence = drm_writeback_get_out_fence(wb_conn);
> > if (!fence)
> > return -ENOMEM;
> > diff --git a/drivers/gpu/drm/drm_writeback.c
> > b/drivers/gpu/drm/drm_writeback.c index 6ba3833a93ca..f93c936643bb
> > 100644
> > --- a/drivers/gpu/drm/drm_writeback.c
> > +++ b/drivers/gpu/drm/drm_writeback.c
> > @@ -95,8 +95,9 @@ static const char
> *drm_writeback_fence_get_driver_name(struct dma_fence *fence)
> > {
> > struct drm_writeback_connector *wb_connector =
> > fence_to_wb_connector(fence);
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_connector);
> >
> > - return wb_connector->base.dev->driver->name;
> > + return connector->dev->driver->name;
> > }
> >
> > static const char *
> > @@ -193,7 +194,7 @@ static int __drm_writeback_connector_init(struct
> drm_device *dev,
> > struct drm_encoder *enc, const u32
> *formats,
> > int n_formats)
> > {
> > - struct drm_connector *connector = &wb_connector->base;
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_connector);
> > struct drm_mode_config *config = &dev->mode_config;
> > struct drm_property_blob *blob;
> > int ret = create_writeback_properties(dev); @@ -275,7 +276,7 @@ int
> > drm_writeback_connector_init(struct drm_device *dev,
> > struct drm_encoder *enc,
> > const u32 *formats, int n_formats)
> > {
> > - struct drm_connector *connector = &wb_connector->base;
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_connector);
> FYI: I missed this before but drm_writeback_connector_init needs to be
> removed. The whole point of Dmitry's patch set is to switch to drmm instead of
> drm init/alloc functions. I don't think it really affects this patch set
> much. But I
> believe the last version of the i915/Xe writeback support was still using the
> manual memory management interface via this function. That will need
> updating to use the drmm version.
>
I think from the last revision of Dmitry's patch series we are currently not
use drmm versions
At least for now
Regards,
Suraj Kandpal
> John.
>
>
> > int ret;
> >
> > ret = drm_connector_init(dev, connector, con_funcs, @@ -345,7
> > +346,7 @@ int drmm_writeback_connector_init(struct drm_device *dev,
> > struct drm_encoder *enc,
> > const u32 *formats, int n_formats)
> > {
> > - struct drm_connector *connector = &wb_connector->base;
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_connector);
> > int ret;
> >
> > ret = drmm_connector_init(dev, connector, con_funcs, @@ -378,7
> > +379,7 @@ int drm_writeback_set_fb(struct drm_connector_state
> *conn_state,
> > return -ENOMEM;
> >
> > conn_state->writeback_job->connector =
> > - drm_connector_to_writeback(conn_state->connector);
> > + &conn_state->connector->writeback;
> > }
> >
> > drm_framebuffer_assign(&conn_state->writeback_job->fb, fb); @@
> > -387,13 +388,14 @@ int drm_writeback_set_fb(struct drm_connector_state
> > *conn_state,
> >
> > int drm_writeback_prepare_job(struct drm_writeback_job *job)
> > {
> > - struct drm_writeback_connector *connector = job->connector;
> > + struct drm_writeback_connector *wb_connector = job->connector;
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_connector);
> > const struct drm_connector_helper_funcs *funcs =
> > - connector->base.helper_private;
> > + connector->helper_private;
> > int ret;
> >
> > if (funcs->prepare_writeback_job) {
> > - ret = funcs->prepare_writeback_job(connector, job);
> > + ret = funcs->prepare_writeback_job(wb_connector, job);
> > if (ret < 0)
> > return ret;
> > }
> > @@ -439,12 +441,13 @@ EXPORT_SYMBOL(drm_writeback_queue_job);
> >
> > void drm_writeback_cleanup_job(struct drm_writeback_job *job)
> > {
> > - struct drm_writeback_connector *connector = job->connector;
> > + struct drm_writeback_connector *wb_connector = job->connector;
> > + struct drm_connector *connector =
> drm_writeback_to_connector(wb_connector);
> > const struct drm_connector_helper_funcs *funcs =
> > - connector->base.helper_private;
> > + connector->helper_private;
> >
> > if (job->prepared && funcs->cleanup_writeback_job)
> > - funcs->cleanup_writeback_job(connector, job);
> > + funcs->cleanup_writeback_job(wb_connector, job);
> >
> > if (job->fb)
> > drm_framebuffer_put(job->fb);
> > @@ -526,8 +529,9 @@ struct dma_fence *
> > drm_writeback_get_out_fence(struct drm_writeback_connector
> *wb_connector)
> > {
> > struct dma_fence *fence;
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_connector);
> >
> > - if (WARN_ON(wb_connector->base.connector_type !=
> > + if (WARN_ON(connector->connector_type !=
> > DRM_MODE_CONNECTOR_WRITEBACK))
> > return NULL;
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> > b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> > index 22433bfbea1e..e2a328225c9e 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> > @@ -481,7 +481,8 @@ static void
> dpu_encoder_phys_wb_prepare_for_kickoff(
> > return;
> > }
> >
> > - drm_conn = &wb_enc->wb_conn->base;
> > + drm_conn =
> > + drm_writeback_to_connector(wb_enc->wb_conn);
> > state = drm_conn->state;
> >
> > if (wb_enc->wb_conn && wb_enc->wb_job) diff --git
> > a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
> > b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
> > index e7b09013ae4c..d1211788625a 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
> > @@ -29,8 +29,7 @@ static int dpu_wb_conn_get_modes(struct
> drm_connector *connector)
> > static int dpu_wb_conn_atomic_check(struct drm_connector *connector,
> > struct drm_atomic_commit *state)
> > {
> > - struct drm_writeback_connector *wb_conn =
> drm_connector_to_writeback(connector);
> > - struct dpu_wb_connector *dpu_wb_conn =
> to_dpu_wb_conn(wb_conn);
> > + struct dpu_wb_connector *dpu_wb_conn =
> to_dpu_wb_conn(connector);
> > struct drm_connector_state *conn_state =
> > drm_atomic_get_new_connector_state(state, connector);
> > struct drm_crtc *crtc;
> > @@ -88,10 +87,10 @@ static const struct drm_connector_funcs
> dpu_wb_conn_funcs = {
> > .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > };
> >
> > -static int dpu_wb_conn_prepare_job(struct drm_writeback_connector
> > *connector,
> > +static int dpu_wb_conn_prepare_job(struct drm_writeback_connector
> > +*wb_conn,
> > struct drm_writeback_job *job)
> > {
> > -
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_conn);
> > struct dpu_wb_connector *dpu_wb_conn =
> to_dpu_wb_conn(connector);
> >
> > if (!job->fb)
> > @@ -102,9 +101,10 @@ static int dpu_wb_conn_prepare_job(struct
> drm_writeback_connector *connector,
> > return 0;
> > }
> >
> > -static void dpu_wb_conn_cleanup_job(struct drm_writeback_connector
> > *connector,
> > +static void dpu_wb_conn_cleanup_job(struct drm_writeback_connector
> > +*wb_connector,
> > struct drm_writeback_job *job)
> > {
> > + struct drm_connector *connector =
> > +drm_writeback_to_connector(wb_connector);
> > struct dpu_wb_connector *dpu_wb_conn =
> to_dpu_wb_conn(connector);
> >
> > if (!job->fb)
> > @@ -132,9 +132,9 @@ int dpu_writeback_init(struct drm_device *dev,
> > struct drm_encoder *enc,
> >
> > dpu_wb_conn->maxlinewidth = maxlinewidth;
> >
> > - drm_connector_helper_add(&dpu_wb_conn->base.base,
> &dpu_wb_conn_helper_funcs);
> > + drm_connector_helper_add(&dpu_wb_conn->base,
> > +&dpu_wb_conn_helper_funcs);
> >
> > - rc = drmm_writeback_connector_init(dev, &dpu_wb_conn->base,
> > + rc = drmm_writeback_connector_init(dev,
> > +&dpu_wb_conn->base.writeback,
> > &dpu_wb_conn_funcs, enc,
> > format_list, num_formats);
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h
> > b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h
> > index 4b11cca8014c..9ebf15392b20 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.h
> > @@ -16,12 +16,12 @@
> > #include "dpu_encoder_phys.h"
> >
> > struct dpu_wb_connector {
> > - struct drm_writeback_connector base;
> > + struct drm_connector base;
> > struct drm_encoder *wb_enc;
> > u32 maxlinewidth;
> > };
> >
> > -static inline struct dpu_wb_connector *to_dpu_wb_conn(struct
> > drm_writeback_connector *conn)
> > +static inline struct dpu_wb_connector *to_dpu_wb_conn(struct
> > +drm_connector *conn)
> > {
> > return container_of(conn, struct dpu_wb_connector, base);
> > }
> > diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.h
> > b/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.h
> > index 8857926e109a..11372ccfdd38 100644
> > --- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.h
> > +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.h
> > @@ -43,7 +43,7 @@ struct rcar_du_vsp;
> > * @cmm: CMM associated with this CRTC
> > * @vsp: VSP feeding video to this CRTC
> > * @vsp_pipe: index of the VSP pipeline feeding video to this CRTC
> > - * @writeback: the writeback connector
> > + * @wb_connector: the drm connector which contains the writeback
> > + connector
> > */
> > struct rcar_du_crtc {
> > struct drm_crtc crtc;
> > @@ -73,11 +73,11 @@ struct rcar_du_crtc {
> > const char *const *sources;
> > unsigned int sources_count;
> >
> > - struct drm_writeback_connector writeback;
> > + struct drm_connector wb_connector;
> > };
> >
> > #define to_rcar_crtc(c) container_of(c, struct rcar_du_crtc,
> crtc)
> > -#define wb_to_rcar_crtc(c) container_of(c, struct rcar_du_crtc, writeback)
> > +#define wb_to_rcar_crtc(c) container_of(c, struct rcar_du_crtc,
> wb_connector)
> >
> > /**
> > * struct rcar_du_crtc_state - Driver-specific CRTC state diff --git
> > a/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
> > b/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
> > index ecfd4fc1f210..39be854c465a 100644
> > --- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
> > +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
> > @@ -50,7 +50,8 @@ static int rcar_du_wb_conn_get_modes(struct
> drm_connector *connector)
> > static int rcar_du_wb_prepare_job(struct drm_writeback_connector
> *connector,
> > struct drm_writeback_job *job)
> > {
> > - struct rcar_du_crtc *rcrtc = wb_to_rcar_crtc(connector);
> > + struct drm_connector *conn =
> drm_writeback_to_connector(connector);
> > + struct rcar_du_crtc *rcrtc = wb_to_rcar_crtc(conn);
> > struct rcar_du_wb_job *rjob;
> > int ret;
> >
> > @@ -75,7 +76,8 @@ static int rcar_du_wb_prepare_job(struct
> drm_writeback_connector *connector,
> > static void rcar_du_wb_cleanup_job(struct drm_writeback_connector
> *connector,
> > struct drm_writeback_job *job)
> > {
> > - struct rcar_du_crtc *rcrtc = wb_to_rcar_crtc(connector);
> > + struct drm_connector *conn =
> drm_writeback_to_connector(connector);
> > + struct rcar_du_crtc *rcrtc = wb_to_rcar_crtc(conn);
> > struct rcar_du_wb_job *rjob = job->priv;
> >
> > if (!job->fb)
> > @@ -199,7 +201,7 @@ static const u32 writeback_formats[] = {
> > int rcar_du_writeback_init(struct rcar_du_device *rcdu,
> > struct rcar_du_crtc *rcrtc)
> > {
> > - struct drm_writeback_connector *wb_conn = &rcrtc->writeback;
> > + struct drm_writeback_connector *wb_conn =
> > +&rcrtc->wb_connector.writeback;
> > struct drm_encoder *encoder;
> >
> > encoder = drmm_plain_encoder_alloc(&rcdu->ddev, NULL, @@ -211,7
> > +213,7 @@ int rcar_du_writeback_init(struct rcar_du_device *rcdu,
> >
> > encoder->possible_crtcs = drm_crtc_mask(&rcrtc->crtc);
> >
> > - drm_connector_helper_add(&wb_conn->base,
> > + drm_connector_helper_add(&rcrtc->wb_connector,
> > &rcar_du_wb_conn_helper_funcs);
> >
> > return drmm_writeback_connector_init(&rcdu->ddev, wb_conn, @@
> > -230,7 +232,7 @@ void rcar_du_writeback_setup(struct rcar_du_crtc *rcrtc,
> > struct drm_framebuffer *fb;
> > unsigned int i;
> >
> > - state = rcrtc->writeback.base.state;
> > + state = rcrtc->wb_connector.state;
> > if (!state || !state->writeback_job)
> > return;
> >
> > @@ -245,10 +247,10 @@ void rcar_du_writeback_setup(struct rcar_du_crtc
> *rcrtc,
> > cfg->mem[i] = sg_dma_address(rjob->sg_tables[i].sgl)
> > + fb->offsets[i];
> >
> > - drm_writeback_queue_job(&rcrtc->writeback, state);
> > + drm_writeback_queue_job(&rcrtc->wb_connector.writeback, state);
> > }
> >
> > void rcar_du_writeback_complete(struct rcar_du_crtc *rcrtc)
> > {
> > - drm_writeback_signal_completion(&rcrtc->writeback, 0);
> > + drm_writeback_signal_completion(&rcrtc->wb_connector.writeback,
> 0);
> > }
> > diff --git a/drivers/gpu/drm/vc4/vc4_txp.c
> > b/drivers/gpu/drm/vc4/vc4_txp.c index 322cc65dc787..864125cc7d72
> > 100644
> > --- a/drivers/gpu/drm/vc4/vc4_txp.c
> > +++ b/drivers/gpu/drm/vc4/vc4_txp.c
> > @@ -167,7 +167,7 @@ struct vc4_txp {
> > struct platform_device *pdev;
> >
> > struct vc4_encoder encoder;
> > - struct drm_writeback_connector connector;
> > + struct drm_connector connector;
> >
> > void __iomem *regs;
> > };
> > @@ -176,7 +176,7 @@ struct vc4_txp {
> > container_of_const(_encoder, struct vc4_txp, encoder.base)
> >
> > #define connector_to_vc4_txp(_connector) \
> > - container_of_const(_connector, struct vc4_txp, connector.base)
> > + container_of_const(_connector, struct vc4_txp, connector)
> >
> > static const struct debugfs_reg32 txp_regs[] = {
> > VC4_REG32(TXP_DST_PTR),
> > @@ -356,7 +356,7 @@ static void vc4_txp_connector_atomic_commit(struct
> > drm_connector *conn,
> >
> > TXP_WRITE(TXP_DST_CTRL, ctrl);
> >
> > - drm_writeback_queue_job(&txp->connector, conn_state);
> > + drm_writeback_queue_job(&txp->connector.writeback, conn_state);
> >
> > drm_dev_exit(idx);
> > }
> > @@ -504,7 +504,7 @@ static irqreturn_t vc4_txp_interrupt(int irq, void
> *data)
> > */
> > TXP_WRITE(TXP_DST_CTRL, TXP_READ(TXP_DST_CTRL) & ~TXP_EI);
> > vc4_crtc_handle_vblank(vc4_crtc);
> > - drm_writeback_signal_completion(&txp->connector, 0);
> > + drm_writeback_signal_completion(&txp->connector.writeback, 0);
> >
> > return IRQ_HANDLED;
> > }
> > @@ -598,9 +598,9 @@ static int vc4_txp_bind(struct device *dev, struct
> device *master, void *data)
> > if (ret)
> > return ret;
> >
> > - drm_connector_helper_add(&txp->connector.base,
> > + drm_connector_helper_add(&txp->connector,
> > &vc4_txp_connector_helper_funcs);
> > - ret = drmm_writeback_connector_init(drm, &txp->connector,
> > + ret = drmm_writeback_connector_init(drm, &txp-
> >connector.writeback,
> > &vc4_txp_connector_funcs,
> > encoder,
> > drm_fmts, ARRAY_SIZE(drm_fmts));
> diff --git
> > a/drivers/gpu/drm/vkms/vkms_composer.c
> > b/drivers/gpu/drm/vkms/vkms_composer.c
> > index 83d217085ad0..27fb6a7b55bb 100644
> > --- a/drivers/gpu/drm/vkms/vkms_composer.c
> > +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> > @@ -652,7 +652,7 @@ void vkms_composer_worker(struct work_struct
> *work)
> > return;
> >
> > if (wb_pending) {
> > - drm_writeback_signal_completion(&out->wb_connector, 0);
> > + drm_writeback_signal_completion(&out-
> >wb_connector.writeback, 0);
> > spin_lock_irq(&out->composer_lock);
> > crtc_state->wb_pending = false;
> > spin_unlock_irq(&out->composer_lock);
> > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h
> > b/drivers/gpu/drm/vkms/vkms_drv.h index 0933e4ce0ff0..145a7909388b
> > 100644
> > --- a/drivers/gpu/drm/vkms/vkms_drv.h
> > +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> > @@ -217,7 +217,7 @@ struct vkms_crtc_state {
> > */
> > struct vkms_output {
> > struct drm_crtc crtc;
> > - struct drm_writeback_connector wb_connector;
> > + struct drm_connector wb_connector;
> > struct drm_encoder wb_encoder;
> > struct workqueue_struct *composer_workq;
> > spinlock_t lock;
> > diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c
> > b/drivers/gpu/drm/vkms/vkms_writeback.c
> > index ecf29a2c0c8e..64d524d2168f 100644
> > --- a/drivers/gpu/drm/vkms/vkms_writeback.c
> > +++ b/drivers/gpu/drm/vkms/vkms_writeback.c
> > @@ -103,10 +103,13 @@ static int vkms_wb_prepare_job(struct
> drm_writeback_connector *wb_connector,
> > return ret;
> > }
> >
> > -static void vkms_wb_cleanup_job(struct drm_writeback_connector
> > *connector,
> > +static void vkms_wb_cleanup_job(struct drm_writeback_connector
> > +*wb_conn,
> > struct drm_writeback_job *job)
> > {
> > struct vkms_writeback_job *vkmsjob = job->priv;
> > + struct drm_connector *connector = container_of(wb_conn,
> > + struct drm_connector,
> > + writeback);
> > struct vkms_output *vkms_output = container_of(connector,
> > struct vkms_output,
> > wb_connector);
> > @@ -128,8 +131,8 @@ static void vkms_wb_atomic_commit(struct
> drm_connector *conn,
> > struct drm_connector_state *connector_state =
> drm_atomic_get_new_connector_state(state,
> >
> conn);
> > struct vkms_output *output =
> drm_crtc_to_vkms_output(connector_state->crtc);
> > - struct drm_writeback_connector *wb_conn = &output->wb_connector;
> > - struct drm_connector_state *conn_state = wb_conn->base.state;
> > + struct drm_writeback_connector *wb_conn = &output-
> >wb_connector.writeback;
> > + struct drm_connector_state *conn_state = output-
> >wb_connector.state;
> > struct vkms_crtc_state *crtc_state = output->composer_state;
> > struct drm_framebuffer *fb = connector_state->writeback_job->fb;
> > u16 crtc_height = crtc_state->base.mode.vdisplay; @@ -167,7 +170,7
> > @@ static const struct drm_connector_helper_funcs
> vkms_wb_conn_helper_funcs = {
> > int vkms_enable_writeback_connector(struct vkms_device *vkmsdev,
> > struct vkms_output *vkms_output)
> > {
> > - struct drm_writeback_connector *wb = &vkms_output-
> >wb_connector;
> > + struct drm_writeback_connector *wb =
> > +&vkms_output->wb_connector.writeback;
> > int ret;
> >
> > ret = drmm_encoder_init(&vkmsdev->drm, &vkms_output-
> >wb_encoder, @@
> > -178,7 +181,7 @@ int vkms_enable_writeback_connector(struct vkms_device
> *vkmsdev,
> > vkms_output->wb_encoder.possible_clones |=
> > drm_encoder_mask(&vkms_output->wb_encoder);
> >
> > - drm_connector_helper_add(&wb->base,
> &vkms_wb_conn_helper_funcs);
> > + drm_connector_helper_add(&vkms_output->wb_connector,
> > +&vkms_wb_conn_helper_funcs);
> >
> > return drmm_writeback_connector_init(&vkmsdev->drm, wb,
> > &vkms_wb_connector_funcs,
> > diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> > index af075c38f4db..b162ce89da37 100644
> > --- a/include/drm/drm_connector.h
> > +++ b/include/drm/drm_connector.h
> > @@ -2094,6 +2094,61 @@ struct drm_connector_cec {
> > void *data;
> > };
> >
> > +/**
> > + * struct drm_writeback_connector - DRM writeback connector */
> > +struct drm_writeback_connector {
> > + /**
> > + * @pixel_formats_blob_ptr:
> > + *
> > + * DRM blob property data for the pixel formats list on writeback
> > + * connectors
> > + * See also drm_writeback_connector_init()
> > + */
> > + struct drm_property_blob *pixel_formats_blob_ptr;
> > +
> > + /** @job_lock: Protects job_queue */
> > + spinlock_t job_lock;
> > +
> > + /**
> > + * @job_queue:
> > + *
> > + * Holds a list of a connector's writeback jobs; the last item is the
> > + * most recent. The first item may be either waiting for the hardware
> > + * to begin writing, or currently being written.
> > + *
> > + * See also: drm_writeback_queue_job() and
> > + * drm_writeback_signal_completion()
> > + */
> > + struct list_head job_queue;
> > +
> > + /**
> > + * @fence_context:
> > + *
> > + * timeline context used for fence operations.
> > + */
> > + unsigned int fence_context;
> > + /**
> > + * @fence_lock:
> > + *
> > + * spinlock to protect the fences in the fence_context.
> > + */
> > + spinlock_t fence_lock;
> > + /**
> > + * @fence_seqno:
> > + *
> > + * Seqno variable used as monotonic counter for the fences
> > + * created on the connector's timeline.
> > + */
> > + unsigned long fence_seqno;
> > + /**
> > + * @timeline_name:
> > + *
> > + * The name of the connector's fence timeline.
> > + */
> > + char timeline_name[32];
> > +};
> > +
> > /**
> > * struct drm_connector - central DRM connector control structure
> > *
> > @@ -2509,10 +2564,16 @@ struct drm_connector {
> > */
> > struct llist_node free_node;
> >
> > - /**
> > - * @hdmi: HDMI-related variable and properties.
> > - */
> > - struct drm_connector_hdmi hdmi;
> > + union {
> > + /**
> > + * @hdmi: HDMI-related variable and properties.
> > + */
> > + struct drm_connector_hdmi hdmi;
> > + /**
> > + * @writeback: Writeback related valriables.
> > + */
> > + struct drm_writeback_connector writeback;
> > + };
> >
> > /**
> > * @hdmi_audio: HDMI codec properties and non-DRM state.
> > diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
> > index 958466a05e60..702141099520 100644
> > --- a/include/drm/drm_writeback.h
> > +++ b/include/drm/drm_writeback.h
> > @@ -15,66 +15,6 @@
> > #include <drm/drm_encoder.h>
> > #include <linux/workqueue.h>
> >
> > -/**
> > - * struct drm_writeback_connector - DRM writeback connector
> > - */
> > -struct drm_writeback_connector {
> > - /**
> > - * @base: base drm_connector object
> > - */
> > - struct drm_connector base;
> > -
> > - /**
> > - * @pixel_formats_blob_ptr:
> > - *
> > - * DRM blob property data for the pixel formats list on writeback
> > - * connectors
> > - * See also drm_writeback_connector_init()
> > - */
> > - struct drm_property_blob *pixel_formats_blob_ptr;
> > -
> > - /** @job_lock: Protects job_queue */
> > - spinlock_t job_lock;
> > -
> > - /**
> > - * @job_queue:
> > - *
> > - * Holds a list of a connector's writeback jobs; the last item is the
> > - * most recent. The first item may be either waiting for the hardware
> > - * to begin writing, or currently being written.
> > - *
> > - * See also: drm_writeback_queue_job() and
> > - * drm_writeback_signal_completion()
> > - */
> > - struct list_head job_queue;
> > -
> > - /**
> > - * @fence_context:
> > - *
> > - * timeline context used for fence operations.
> > - */
> > - unsigned int fence_context;
> > - /**
> > - * @fence_lock:
> > - *
> > - * spinlock to protect the fences in the fence_context.
> > - */
> > - spinlock_t fence_lock;
> > - /**
> > - * @fence_seqno:
> > - *
> > - * Seqno variable used as monotonic counter for the fences
> > - * created on the connector's timeline.
> > - */
> > - unsigned long fence_seqno;
> > - /**
> > - * @timeline_name:
> > - *
> > - * The name of the connector's fence timeline.
> > - */
> > - char timeline_name[32];
> > -};
> > -
> > /**
> > * struct drm_writeback_job - DRM writeback job
> > */
> > @@ -131,10 +71,10 @@ struct drm_writeback_job {
> > void *priv;
> > };
> >
> > -static inline struct drm_writeback_connector *
> > -drm_connector_to_writeback(struct drm_connector *connector)
> > +static inline struct drm_connector *
> > +drm_writeback_to_connector(struct drm_writeback_connector
> > +*wb_connector)
> > {
> > - return container_of(connector, struct drm_writeback_connector, base);
> > + return container_of(wb_connector, struct drm_connector, writeback);
> > }
> >
> > int drm_writeback_connector_init(struct drm_device *dev,
