There are some vendor drivers for which the writeback encoder shares hardware resources such as clocks and interrupts with the rest of the display pipeline. In addition, there can be use-cases where the writeback encoder could be a shared encoder between the physical display path and the writeback path.
To accommodate for such cases, change the drm_writeback_connector to accept a pointer to drm_encoder.
For existing users of drm_writeback_connector there will not be any change in functionality due to this change.
This approach was first posted by Suraj Kandpal here [1] for both encoder and connector. But after discussions [2], the consensus was reached to split this change for the drm_encoder first and the drm_connector part can be reworked in a subsequent change later.
Validation of this change was done using igt_writeback tests on MSM based RB5 board using the changes posted here [3].
For all other chipsets, these changes were compile-tested.
[1] https://patchwork.kernel.org/project/dri-devel/patch/20220202081702.22119-1-... [2] https://patchwork.kernel.org/project/dri-devel/patch/20220202085429.22261-6-... [3] https://patchwork.freedesktop.org/series/99724/
changes in v2: - introduce a new API drm_writeback_connector_init_with_encoder() - allow passing possible_crtcs for existing users of drm_writeback_connector_init()
Abhinav Kumar (6): drm: allow real encoder to be passed for drm_writeback_connector drm/komeda: pass possible_crtcs as parameter for drm_writeback_connector drm/vkms: pass possible_crtcs as parameter for drm_writeback_connector drm/vc4: change vc4 driver to use drm_writeback_connector_init_with_encoder() drm/rcar_du: pass possible_crtcs as parameter for drm_writeback_connector drm/malidp: pass possible_crtcs as parameter for drm_writeback_connector
.../drm/arm/display/komeda/komeda_wb_connector.c | 3 +- drivers/gpu/drm/arm/malidp_mw.c | 5 +- drivers/gpu/drm/drm_writeback.c | 144 +++++++++++++++------ drivers/gpu/drm/rcar-du/rcar_du_writeback.c | 5 +- drivers/gpu/drm/vc4/vc4_txp.c | 30 ++++- drivers/gpu/drm/vkms/vkms_writeback.c | 3 +- include/drm/drm_writeback.h | 27 +++- 7 files changed, 161 insertions(+), 56 deletions(-)
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 using a new drm_writeback_connector_init_with_encoder() API.
In addition, to preserve the same call flows for the existing users of drm_writeback_connector_init(), also allow passing possible_crtcs as a parameter so that encoder can be initialized with it.
changes in v2: - introduce a new API drm_writeback_connector_init_with_encoder() - allow passing possible_crtcs for existing users of drm_writeback_connector_init()
Co-developed-by: Kandpal Suraj suraj.kandpal@intel.com Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com --- drivers/gpu/drm/drm_writeback.c | 144 +++++++++++++++++++++++++++++----------- include/drm/drm_writeback.h | 27 +++++++- 2 files changed, 129 insertions(+), 42 deletions(-)
diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c index dccf4504..9277dcb 100644 --- a/drivers/gpu/drm/drm_writeback.c +++ b/drivers/gpu/drm/drm_writeback.c @@ -149,36 +149,15 @@ static const struct drm_encoder_funcs drm_writeback_encoder_funcs = { .destroy = drm_encoder_cleanup, };
-/** - * drm_writeback_connector_init - Initialize a writeback connector and its properties - * @dev: DRM device - * @wb_connector: Writeback connector to initialize - * @con_funcs: Connector funcs vtable - * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder - * @formats: Array of supported pixel formats for the writeback engine - * @n_formats: Length of the formats array - * - * This function creates the writeback-connector-specific properties if they - * have not been already created, initializes the connector as - * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property - * values. It will also create an internal encoder associated with the - * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for - * the encoder helper. - * - * Drivers should always use this function instead of drm_connector_init() to - * set up writeback connectors. - * - * Returns: 0 on success, or a negative error code - */ -int drm_writeback_connector_init(struct drm_device *dev, - struct drm_writeback_connector *wb_connector, - const struct drm_connector_funcs *con_funcs, - const struct drm_encoder_helper_funcs *enc_helper_funcs, - const u32 *formats, int n_formats) +static int drm_writeback_connector_setup(struct drm_device *dev, + struct drm_writeback_connector *wb_connector, + const struct drm_connector_funcs *con_funcs, const u32 *formats, + int n_formats) { struct drm_property_blob *blob; - struct drm_connector *connector = &wb_connector->base; struct drm_mode_config *config = &dev->mode_config; + struct drm_connector *connector = &wb_connector->base; + int ret = create_writeback_properties(dev);
if (ret != 0) @@ -186,15 +165,10 @@ int drm_writeback_connector_init(struct drm_device *dev,
blob = drm_property_create_blob(dev, n_formats * sizeof(*formats), formats); - if (IS_ERR(blob)) - return PTR_ERR(blob); - - drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs); - ret = drm_encoder_init(dev, &wb_connector->encoder, - &drm_writeback_encoder_funcs, - DRM_MODE_ENCODER_VIRTUAL, NULL); - if (ret) - goto fail; + if (IS_ERR(blob)) { + ret = PTR_ERR(blob); + return ret; + }
connector->interlace_allowed = 0;
@@ -204,7 +178,7 @@ int drm_writeback_connector_init(struct drm_device *dev, goto connector_fail;
ret = drm_connector_attach_encoder(connector, - &wb_connector->encoder); + wb_connector->encoder); if (ret) goto attach_fail;
@@ -233,13 +207,105 @@ int drm_writeback_connector_init(struct drm_device *dev, attach_fail: drm_connector_cleanup(connector); connector_fail: - drm_encoder_cleanup(&wb_connector->encoder); -fail: drm_property_blob_put(blob); return ret; } + +/** + * drm_writeback_connector_init - Initialize a writeback connector and its properties + * using an internal encoder + * + * @dev: DRM device + * @wb_connector: Writeback connector to initialize + * @con_funcs: Connector funcs vtable + * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder + * @formats: Array of supported pixel formats for the writeback engine + * @n_formats: Length of the formats array + * + * This function creates the writeback-connector-specific properties if they + * have not been already created, initializes the connector as + * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property + * values. It will also create an internal encoder associated with the + * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for + * the encoder helper. + * + * Drivers should always use this function instead of drm_connector_init() to + * set up writeback connectors. + * + * Returns: 0 on success, or a negative error code + */ +int drm_writeback_connector_init(struct drm_device *dev, + struct drm_writeback_connector *wb_connector, + const struct drm_connector_funcs *con_funcs, + const struct drm_encoder_helper_funcs *enc_helper_funcs, + const u32 *formats, int n_formats, uint32_t possible_crtcs) +{ + int ret = 0; + + wb_connector->encoder = &wb_connector->internal_encoder; + + drm_encoder_helper_add(wb_connector->encoder, enc_helper_funcs); + + wb_connector->encoder->possible_crtcs = possible_crtcs; + + ret = drm_encoder_init(dev, wb_connector->encoder, + &drm_writeback_encoder_funcs, + DRM_MODE_ENCODER_VIRTUAL, NULL); + if (ret) + return ret; + + ret = drm_writeback_connector_setup(dev, wb_connector, con_funcs, formats, + n_formats); + + if (ret) + drm_encoder_cleanup(wb_connector->encoder); + + return ret; +} EXPORT_SYMBOL(drm_writeback_connector_init);
+/** + * drm_writeback_connector_init_with_encoder - Initialize a writeback connector and its properties + * using the encoder which already assigned and initialized + * + * @dev: DRM device + * @wb_connector: Writeback connector to initialize + * @con_funcs: Connector funcs vtable + * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder + * @formats: Array of supported pixel formats for the writeback engine + * @n_formats: Length of the formats array + * + * This function creates the writeback-connector-specific properties if they + * have not been already created, initializes the connector as + * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property + * values. + * + * This function assumes that the drm_writebac_connector's encoder has already been + * created and initialized before invoking this function. + * + * In addition, this function also assumes that callers of this API will manage + * assigning the encoder helper functions, possible_crtcs and any other encoder + * specific operation which is otherwise handled by drm_writeback_connector_init(). + * + * Drivers should always use this function instead of drm_connector_init() to + * set up writeback connectors. + * + * Returns: 0 on success, or a negative error code + */ +int drm_writeback_connector_init_with_encoder(struct drm_device *dev, + struct drm_writeback_connector *wb_connector, + const struct drm_connector_funcs *con_funcs, const u32 *formats, + int n_formats) +{ + int ret = 0; + + ret = drm_writeback_connector_setup(dev, wb_connector, con_funcs, formats, + n_formats); + + return ret; +} +EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder); + int drm_writeback_set_fb(struct drm_connector_state *conn_state, struct drm_framebuffer *fb) { diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h index 9697d27..5e752c8 100644 --- a/include/drm/drm_writeback.h +++ b/include/drm/drm_writeback.h @@ -25,13 +25,29 @@ 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 + * a real encoder is not provided by the vendor drm drivers. + * @encoder will be assigned to this for those cases. + */ + struct drm_encoder internal_encoder;
/** * @pixel_formats_blob_ptr: @@ -150,7 +166,12 @@ int drm_writeback_connector_init(struct drm_device *dev, struct drm_writeback_connector *wb_connector, const struct drm_connector_funcs *con_funcs, const struct drm_encoder_helper_funcs *enc_helper_funcs, - const u32 *formats, int n_formats); + const u32 *formats, int n_formats, uint32_t possible_crtcs); + +int drm_writeback_connector_init_with_encoder(struct drm_device *dev, + struct drm_writeback_connector *wb_connector, + const struct drm_connector_funcs *con_funcs, const u32 *formats, + int n_formats);
int drm_writeback_set_fb(struct drm_connector_state *conn_state, struct drm_framebuffer *fb);
As part of this series, drm_writeback_connector_init() allows passing possible_crtcs as a parameter so that the API can internally create and setup the encoder.
Pass possible_crtcs parameter for drm_writeback_connector_init() for komeda driver.
changes in v2: - pass possible_crtcs parameter for drm_writeback_connector_init()
Co-developed-by: Kandpal Suraj suraj.kandpal@intel.com Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com --- drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
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 e465cc4..40774e6 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c @@ -155,7 +155,6 @@ 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->encoder.possible_crtcs = BIT(drm_crtc_index(&kcrtc->base));
formats = komeda_get_layer_fourcc_list(&mdev->fmt_tbl, kwb_conn->wb_layer->layer_type, @@ -164,7 +163,7 @@ static int komeda_wb_connector_add(struct komeda_kms_dev *kms, err = drm_writeback_connector_init(&kms->base, wb_conn, &komeda_wb_connector_funcs, &komeda_wb_encoder_helper_funcs, - formats, n_formats); + formats, n_formats, BIT(drm_crtc_index(&kcrtc->base))); komeda_put_fourcc_list(formats); if (err) { kfree(kwb_conn);
As part of this series, drm_writeback_connector_init() allows passing possible_crtcs as a parameter so that the API can internally create and setup the encoder.
Pass possible_crtcs parameter for drm_writeback_connector_init() for vkms driver.
changes in v2: - pass possible_crtcs parameter for drm_writeback_connector_init()
Co-developed-by: Kandpal Suraj suraj.kandpal@intel.com Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com --- drivers/gpu/drm/vkms/vkms_writeback.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c b/drivers/gpu/drm/vkms/vkms_writeback.c index 8694227..381e7b7 100644 --- a/drivers/gpu/drm/vkms/vkms_writeback.c +++ b/drivers/gpu/drm/vkms/vkms_writeback.c @@ -140,12 +140,11 @@ int vkms_enable_writeback_connector(struct vkms_device *vkmsdev) { struct drm_writeback_connector *wb = &vkmsdev->output.wb_connector;
- vkmsdev->output.wb_connector.encoder.possible_crtcs = 1; drm_connector_helper_add(&wb->base, &vkms_wb_conn_helper_funcs);
return drm_writeback_connector_init(&vkmsdev->drm, wb, &vkms_wb_connector_funcs, &vkms_wb_encoder_helper_funcs, vkms_wb_formats, - ARRAY_SIZE(vkms_wb_formats)); + ARRAY_SIZE(vkms_wb_formats), 1); }
vc4 driver currently embeds the drm_encoder into struct vc4_txp and later on uses container_of to retrieve the vc4_txp from the drm_encoder.
Since drm_encoder has now been made a pointer inside drm_writeback_connector, make vc4 driver use the new API so that the embedded encoder model can be retained in the driver and there is no change in functionality.
changes in v2: - make vc4 driver use drm_writeback_connector_init_with_encoder()
Co-developed-by: Kandpal Suraj suraj.kandpal@intel.com Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com --- drivers/gpu/drm/vc4/vc4_txp.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c index 9809ca3..b09440d 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) @@ -368,6 +370,10 @@ static const struct drm_encoder_helper_funcs vc4_txp_encoder_helper_funcs = { .disable = vc4_txp_encoder_disable, };
+static const struct drm_encoder_funcs vc4_txp_encoder_funcs = { + .destroy = drm_encoder_cleanup, +}; + static int vc4_txp_enable_vblank(struct drm_crtc *crtc) { return 0; @@ -467,6 +473,7 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data) struct vc4_txp *txp; struct drm_crtc *crtc; struct drm_encoder *encoder; + struct drm_writeback_connector *wb_conn; int ret, irq;
irq = platform_get_irq(pdev, 0); @@ -492,21 +499,32 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data) txp->regset.regs = txp_regs; txp->regset.nregs = ARRAY_SIZE(txp_regs);
- drm_connector_helper_add(&txp->connector.base, + wb_conn = &txp->connector; + wb_conn->encoder = &txp->drm_enc; + drm_encoder_helper_add(wb_conn->encoder, &vc4_txp_encoder_helper_funcs); + + ret = drm_encoder_init(drm, wb_conn->encoder, + &vc4_txp_encoder_funcs, + DRM_MODE_ENCODER_VIRTUAL, NULL); + if (ret) + return ret; + + drm_connector_helper_add(&wb_conn->base, &vc4_txp_connector_helper_funcs); - ret = drm_writeback_connector_init(drm, &txp->connector, + ret = drm_writeback_connector_init_with_encoder(drm, wb_conn, &vc4_txp_connector_funcs, - &vc4_txp_encoder_helper_funcs, drm_fmts, ARRAY_SIZE(drm_fmts)); - if (ret) + if (ret) { + drm_encoder_cleanup(wb_conn->encoder); return ret; + }
ret = vc4_crtc_init(drm, vc4_crtc, &vc4_txp_crtc_funcs, &vc4_txp_crtc_helper_funcs); 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,
As part of this series, drm_writeback_connector_init() allows passing possible_crtcs as a parameter so that the API can internally create and setup the encoder.
Pass possible_crtcs parameter for drm_writeback_connector_init() for rcar-du writeback driver.
changes in v2: - pass possible_crtcs parameter for drm_writeback_connector_init()
Co-developed-by: Kandpal Suraj suraj.kandpal@intel.com Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com --- drivers/gpu/drm/rcar-du/rcar_du_writeback.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_writeback.c b/drivers/gpu/drm/rcar-du/rcar_du_writeback.c index c79d125..1a610c0 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_writeback.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_writeback.c @@ -199,8 +199,9 @@ int rcar_du_writeback_init(struct rcar_du_device *rcdu, struct rcar_du_crtc *rcrtc) { struct drm_writeback_connector *wb_conn = &rcrtc->writeback; + uint32_t possible_crtcs;
- wb_conn->encoder.possible_crtcs = 1 << drm_crtc_index(&rcrtc->crtc); + possible_crtcs = 1 << drm_crtc_index(&rcrtc->crtc); drm_connector_helper_add(&wb_conn->base, &rcar_du_wb_conn_helper_funcs);
@@ -208,7 +209,7 @@ int rcar_du_writeback_init(struct rcar_du_device *rcdu, &rcar_du_wb_conn_funcs, &rcar_du_wb_enc_helper_funcs, writeback_formats, - ARRAY_SIZE(writeback_formats)); + ARRAY_SIZE(writeback_formats), possible_crtcs); }
void rcar_du_writeback_setup(struct rcar_du_crtc *rcrtc,
As part of this series, drm_writeback_connector_init() allows passing possible_crtcs as a parameter so that the API can internally create and setup the encoder.
Pass possible_crtcs parameter for drm_writeback_connector_init() for malidp writeback driver.
changes in v2: - pass possible_crtcs parameter for drm_writeback_connector_init()
Co-developed-by: Kandpal Suraj suraj.kandpal@intel.com Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com --- drivers/gpu/drm/arm/malidp_mw.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c index f5847a7..b882066 100644 --- a/drivers/gpu/drm/arm/malidp_mw.c +++ b/drivers/gpu/drm/arm/malidp_mw.c @@ -208,11 +208,12 @@ int malidp_mw_connector_init(struct drm_device *drm) struct malidp_drm *malidp = drm->dev_private; u32 *formats; int ret, n_formats; + uint32_t possible_crtcs;
if (!malidp->dev->hw->enable_memwrite) return 0;
- malidp->mw_connector.encoder.possible_crtcs = 1 << drm_crtc_index(&malidp->crtc); + possible_crtcs = 1 << drm_crtc_index(&malidp->crtc); drm_connector_helper_add(&malidp->mw_connector.base, &malidp_mw_connector_helper_funcs);
@@ -223,7 +224,7 @@ int malidp_mw_connector_init(struct drm_device *drm) ret = drm_writeback_connector_init(drm, &malidp->mw_connector, &malidp_mw_connector_funcs, &malidp_mw_encoder_helper_funcs, - formats, n_formats); + formats, n_formats, possible_crtcs); kfree(formats); if (ret) return ret;
Hi Abhinav,
On 16/03/2022 02:11, Abhinav Kumar wrote:
There are some vendor drivers for which the writeback encoder shares hardware resources such as clocks and interrupts with the rest of the display pipeline. In addition, there can be use-cases where the writeback encoder could be a shared encoder between the physical display path and the writeback path.
To accommodate for such cases, change the drm_writeback_connector to accept a pointer to drm_encoder.
For existing users of drm_writeback_connector there will not be any change in functionality due to this change.
This approach was first posted by Suraj Kandpal here [1] for both encoder and connector. But after discussions [2], the consensus was reached to split this change for the drm_encoder first and the drm_connector part can be reworked in a subsequent change later.
Validation of this change was done using igt_writeback tests on MSM based RB5 board using the changes posted here [3].
For all other chipsets, these changes were compile-tested.
[1] https://patchwork.kernel.org/project/dri-devel/patch/20220202081702.22119-1-... [2] https://patchwork.kernel.org/project/dri-devel/patch/20220202085429.22261-6-... [3] https://patchwork.freedesktop.org/series/99724/
changes in v2: - introduce a new API drm_writeback_connector_init_with_encoder() - allow passing possible_crtcs for existing users of drm_writeback_connector_init()
Abhinav Kumar (6): drm: allow real encoder to be passed for drm_writeback_connector drm/komeda: pass possible_crtcs as parameter for drm_writeback_connector drm/vkms: pass possible_crtcs as parameter for drm_writeback_connector drm/vc4: change vc4 driver to use drm_writeback_connector_init_with_encoder() drm/rcar_du: pass possible_crtcs as parameter for drm_writeback_connector drm/malidp: pass possible_crtcs as parameter for drm_writeback_connector
I think we expect that at each commit point the kernel should be compilable. Could you please squash patches accordingly?
I'd suggest the following patch sequence:
- Add possible_crtcs to the drm_writeback_connector_init() including all the driver changes (all drivers must be compilable, including vc4) - Add drm_writeback_connector_init_with_encoder() - Modify vc4 to use new API
WDYT?
.../drm/arm/display/komeda/komeda_wb_connector.c | 3 +- drivers/gpu/drm/arm/malidp_mw.c | 5 +- drivers/gpu/drm/drm_writeback.c | 144 +++++++++++++++------ drivers/gpu/drm/rcar-du/rcar_du_writeback.c | 5 +- drivers/gpu/drm/vc4/vc4_txp.c | 30 ++++- drivers/gpu/drm/vkms/vkms_writeback.c | 3 +- include/drm/drm_writeback.h | 27 +++- 7 files changed, 161 insertions(+), 56 deletions(-)
Hi Dmitry
On 3/16/2022 12:40 AM, Dmitry Baryshkov wrote:
Hi Abhinav,
On 16/03/2022 02:11, Abhinav Kumar wrote:
There are some vendor drivers for which the writeback encoder shares hardware resources such as clocks and interrupts with the rest of the display pipeline. In addition, there can be use-cases where the writeback encoder could be a shared encoder between the physical display path and the writeback path.
To accommodate for such cases, change the drm_writeback_connector to accept a pointer to drm_encoder.
For existing users of drm_writeback_connector there will not be any change in functionality due to this change.
This approach was first posted by Suraj Kandpal here [1] for both encoder and connector. But after discussions [2], the consensus was reached to split this change for the drm_encoder first and the drm_connector part can be reworked in a subsequent change later.
Validation of this change was done using igt_writeback tests on MSM based RB5 board using the changes posted here [3].
For all other chipsets, these changes were compile-tested.
[1] https://patchwork.kernel.org/project/dri-devel/patch/20220202081702.22119-1-...
[2] https://patchwork.kernel.org/project/dri-devel/patch/20220202085429.22261-6-...
[3] https://patchwork.freedesktop.org/series/99724/
changes in v2: - introduce a new API drm_writeback_connector_init_with_encoder() - allow passing possible_crtcs for existing users of drm_writeback_connector_init()
Abhinav Kumar (6): drm: allow real encoder to be passed for drm_writeback_connector drm/komeda: pass possible_crtcs as parameter for drm_writeback_connector drm/vkms: pass possible_crtcs as parameter for drm_writeback_connector drm/vc4: change vc4 driver to use drm_writeback_connector_init_with_encoder() drm/rcar_du: pass possible_crtcs as parameter for drm_writeback_connector drm/malidp: pass possible_crtcs as parameter for drm_writeback_connector
I think we expect that at each commit point the kernel should be compilable. Could you please squash patches accordingly?
I'd suggest the following patch sequence:
- Add possible_crtcs to the drm_writeback_connector_init() including all
the driver changes (all drivers must be compilable, including vc4)
- Add drm_writeback_connector_init_with_encoder()
- Modify vc4 to use new API
WDYT?
Yes I also thought if each commit point should be compilable. The way this started out was that in the original series https://patchwork.kernel.org/project/dri-devel/patch/20220202081702.22119-1-... every commit was separated vendor-wise even though it will not compile individually.
So I thought that, for ease of code-review perhaps it was alright to separate it that way so that individual vendors can review separately.
But if we need to make each of the commits compilable we will have to squash the way you have mentioned.
.../drm/arm/display/komeda/komeda_wb_connector.c | 3 +- drivers/gpu/drm/arm/malidp_mw.c | 5 +- drivers/gpu/drm/drm_writeback.c | 144 +++++++++++++++------ drivers/gpu/drm/rcar-du/rcar_du_writeback.c | 5 +- drivers/gpu/drm/vc4/vc4_txp.c | 30 ++++- drivers/gpu/drm/vkms/vkms_writeback.c | 3 +- include/drm/drm_writeback.h | 27 +++- 7 files changed, 161 insertions(+), 56 deletions(-)
dri-devel@lists.freedesktop.org
-
Abhinav Kumar -
Dmitry Baryshkov