This is something that we've wanted for a while now: the ability to actually look up the respective drm_device for a given drm_dp_aux struct. This will also allow us to transition over to using the drm_dbg_*() helpers for debug message printing, as we'll finally have a drm_device to reference for doing so.
Note that there is one limitation with this - because some DP AUX adapters exist as platform devices which are initialized independently of their respective DRM devices, one cannot rely on drm_dp_aux->drm_dev to always be non-NULL until drm_dp_aux_register() has been called. We make sure to point this out in the documentation for struct drm_dp_aux.
v3: * Add WARN_ON_ONCE() to drm_dp_aux_register() if drm_dev isn't filled out
Signed-off-by: Lyude Paul lyude@redhat.com Acked-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/amd/amdgpu/atombios_dp.c | 2 ++ .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 1 + drivers/gpu/drm/bridge/analogix/analogix-anx6345.c | 1 + drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c | 1 + drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 1 + drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 1 + drivers/gpu/drm/bridge/tc358767.c | 1 + drivers/gpu/drm/bridge/ti-sn65dsi86.c | 1 + drivers/gpu/drm/drm_dp_aux_dev.c | 6 ++++++ drivers/gpu/drm/drm_dp_helper.c | 2 ++ drivers/gpu/drm/drm_dp_mst_topology.c | 1 + drivers/gpu/drm/i915/display/intel_dp_aux.c | 1 + drivers/gpu/drm/msm/edp/edp.h | 3 +-- drivers/gpu/drm/msm/edp/edp_aux.c | 5 +++-- drivers/gpu/drm/msm/edp/edp_ctrl.c | 2 +- drivers/gpu/drm/nouveau/nouveau_connector.c | 1 + drivers/gpu/drm/radeon/atombios_dp.c | 1 + drivers/gpu/drm/tegra/dpaux.c | 1 + drivers/gpu/drm/xlnx/zynqmp_dp.c | 1 + include/drm/drm_dp_helper.h | 9 ++++++++- 20 files changed, 36 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c index a3ba9ca11e98..062625a8a4ec 100644 --- a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c +++ b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c @@ -188,6 +188,8 @@ void amdgpu_atombios_dp_aux_init(struct amdgpu_connector *amdgpu_connector) { amdgpu_connector->ddc_bus->rec.hpd = amdgpu_connector->hpd.hpd; amdgpu_connector->ddc_bus->aux.transfer = amdgpu_atombios_dp_aux_transfer; + amdgpu_connector->ddc_bus->aux.drm_dev = amdgpu_connector->base.dev; + drm_dp_aux_init(&amdgpu_connector->ddc_bus->aux); amdgpu_connector->ddc_bus->has_aux = true; } diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 73cdb9fe981a..997567f6f0ba 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -433,6 +433,7 @@ void amdgpu_dm_initialize_dp_connector(struct amdgpu_display_manager *dm, kasprintf(GFP_KERNEL, "AMDGPU DM aux hw bus %d", link_index); aconnector->dm_dp_aux.aux.transfer = dm_dp_aux_transfer; + aconnector->dm_dp_aux.aux.drm_dev = dm->ddev; aconnector->dm_dp_aux.ddc_service = aconnector->dc_link->ddc;
drm_dp_aux_init(&aconnector->dm_dp_aux.aux); diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c index aa6cda458eb9..e33cd077595a 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c +++ b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c @@ -537,6 +537,7 @@ static int anx6345_bridge_attach(struct drm_bridge *bridge, /* Register aux channel */ anx6345->aux.name = "DP-AUX"; anx6345->aux.dev = &anx6345->client->dev; + anx6345->aux.drm_dev = bridge->dev; anx6345->aux.transfer = anx6345_aux_transfer;
err = drm_dp_aux_register(&anx6345->aux); diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c index f20558618220..5e6a0ed39199 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c +++ b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c @@ -905,6 +905,7 @@ static int anx78xx_bridge_attach(struct drm_bridge *bridge, /* Register aux channel */ anx78xx->aux.name = "DP-AUX"; anx78xx->aux.dev = &anx78xx->client->dev; + anx78xx->aux.drm_dev = bridge->dev; anx78xx->aux.transfer = anx78xx_aux_transfer;
err = drm_dp_aux_register(&anx78xx->aux); diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index f115233b1cb9..550814ca2139 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1765,6 +1765,7 @@ int analogix_dp_bind(struct analogix_dp_device *dp, struct drm_device *drm_dev) dp->aux.name = "DP-AUX"; dp->aux.transfer = analogix_dpaux_transfer; dp->aux.dev = dp->dev; + dp->aux.drm_dev = drm_dev;
ret = drm_dp_aux_register(&dp->aux); if (ret) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 49e4c340f1de..0cd8f40fb690 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -1719,6 +1719,7 @@ static int cdns_mhdp_attach(struct drm_bridge *bridge,
dev_dbg(mhdp->dev, "%s\n", __func__);
+ mhdp->aux.drm_dev = bridge->dev; ret = drm_dp_aux_register(&mhdp->aux); if (ret < 0) return ret; diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index da89922721ed..23a6f90b694b 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -1414,6 +1414,7 @@ static int tc_bridge_attach(struct drm_bridge *bridge, if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) return 0;
+ tc->aux.drm_dev = drm; ret = drm_dp_aux_register(&tc->aux); if (ret < 0) return ret; diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 51db30d573c1..56706714561f 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -350,6 +350,7 @@ static int ti_sn_bridge_attach(struct drm_bridge *bridge, return -EINVAL; }
+ pdata->aux.drm_dev = bridge->dev; ret = drm_dp_aux_register(&pdata->aux); if (ret < 0) { drm_err(bridge->dev, "Failed to register DP AUX channel: %d\n", ret); diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c b/drivers/gpu/drm/drm_dp_aux_dev.c index e25181bf2c48..06b374cae956 100644 --- a/drivers/gpu/drm/drm_dp_aux_dev.c +++ b/drivers/gpu/drm/drm_dp_aux_dev.c @@ -278,6 +278,12 @@ void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux) if (!aux_dev) /* attach must have failed */ return;
+ /* + * As some AUX adapters may exist as platform devices which outlive their respective DRM + * devices, we clear drm_dev to ensure that we never accidentally reference a stale pointer + */ + aux->drm_dev = NULL; + mutex_lock(&aux_idr_mutex); idr_remove(&aux_idr, aux_dev->index); mutex_unlock(&aux_idr_mutex); diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index cb2f53e56685..ad73d7264743 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1767,6 +1767,8 @@ int drm_dp_aux_register(struct drm_dp_aux *aux) { int ret;
+ WARN_ON_ONCE(!aux->drm_dev); + if (!aux->ddc.algo) drm_dp_aux_init(aux);
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 159014455fab..276f7f054d62 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2350,6 +2350,7 @@ drm_dp_mst_add_port(struct drm_device *dev, port->aux.is_remote = true;
/* initialize the MST downstream port's AUX crc work queue */ + port->aux.drm_dev = dev; drm_dp_remote_aux_init(&port->aux);
/* diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c index 7e83bc2cc34a..c4b446d6a042 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c @@ -682,6 +682,7 @@ void intel_dp_aux_init(struct intel_dp *intel_dp) else intel_dp->get_aux_send_ctl = g4x_get_aux_send_ctl;
+ intel_dp->aux.drm_dev = &dev_priv->drm; drm_dp_aux_init(&intel_dp->aux);
/* Failure to allocate our preferred name is not critical */ diff --git a/drivers/gpu/drm/msm/edp/edp.h b/drivers/gpu/drm/msm/edp/edp.h index eb34243dad53..8590f2ce274d 100644 --- a/drivers/gpu/drm/msm/edp/edp.h +++ b/drivers/gpu/drm/msm/edp/edp.h @@ -46,8 +46,7 @@ void edp_bridge_destroy(struct drm_bridge *bridge); struct drm_connector *msm_edp_connector_init(struct msm_edp *edp);
/* AUX */ -void *msm_edp_aux_init(struct device *dev, void __iomem *regbase, - struct drm_dp_aux **drm_aux); +void *msm_edp_aux_init(struct msm_edp *edp, void __iomem *regbase, struct drm_dp_aux **drm_aux); void msm_edp_aux_destroy(struct device *dev, struct edp_aux *aux); irqreturn_t msm_edp_aux_irq(struct edp_aux *aux, u32 isr); void msm_edp_aux_ctrl(struct edp_aux *aux, int enable); diff --git a/drivers/gpu/drm/msm/edp/edp_aux.c b/drivers/gpu/drm/msm/edp/edp_aux.c index df10a0196d94..e3d85c622cfb 100644 --- a/drivers/gpu/drm/msm/edp/edp_aux.c +++ b/drivers/gpu/drm/msm/edp/edp_aux.c @@ -184,9 +184,9 @@ static ssize_t edp_aux_transfer(struct drm_dp_aux *drm_aux, return ret; }
-void *msm_edp_aux_init(struct device *dev, void __iomem *regbase, - struct drm_dp_aux **drm_aux) +void *msm_edp_aux_init(struct msm_edp *edp, void __iomem *regbase, struct drm_dp_aux **drm_aux) { + struct device *dev = &edp->pdev->dev; struct edp_aux *aux = NULL; int ret;
@@ -201,6 +201,7 @@ void *msm_edp_aux_init(struct device *dev, void __iomem *regbase,
aux->drm_aux.name = "msm_edp_aux"; aux->drm_aux.dev = dev; + aux->drm_aux.drm_dev = edp->dev; aux->drm_aux.transfer = edp_aux_transfer; ret = drm_dp_aux_register(&aux->drm_aux); if (ret) { diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c index 0d9657cc70db..57af3d8b6699 100644 --- a/drivers/gpu/drm/msm/edp/edp_ctrl.c +++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c @@ -1153,7 +1153,7 @@ int msm_edp_ctrl_init(struct msm_edp *edp) }
/* Init aux and phy */ - ctrl->aux = msm_edp_aux_init(dev, ctrl->base, &ctrl->drm_aux); + ctrl->aux = msm_edp_aux_init(edp, ctrl->base, &ctrl->drm_aux); if (!ctrl->aux || !ctrl->drm_aux) { pr_err("%s:failed to init aux\n", __func__); return -ENOMEM; diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c index c04044be3d32..7f38788a6c2b 100644 --- a/drivers/gpu/drm/nouveau/nouveau_connector.c +++ b/drivers/gpu/drm/nouveau/nouveau_connector.c @@ -1354,6 +1354,7 @@ nouveau_connector_create(struct drm_device *dev, case DRM_MODE_CONNECTOR_DisplayPort: case DRM_MODE_CONNECTOR_eDP: nv_connector->aux.dev = connector->kdev; + nv_connector->aux.drm_dev = dev; nv_connector->aux.transfer = nouveau_connector_aux_xfer; snprintf(aux_name, sizeof(aux_name), "sor-%04x-%04x", dcbe->hasht, dcbe->hashm); diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index 15b00a347560..c50c504bad50 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -232,6 +232,7 @@ void radeon_dp_aux_init(struct radeon_connector *radeon_connector)
radeon_connector->ddc_bus->rec.hpd = radeon_connector->hpd.hpd; radeon_connector->ddc_bus->aux.dev = radeon_connector->base.kdev; + radeon_connector->ddc_bus->aux.drm_dev = radeon_connector->base.dev; if (ASIC_IS_DCE5(rdev)) { if (radeon_auxch) radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_native; diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c index ea56c6ec25e4..7d7cc90b6fc9 100644 --- a/drivers/gpu/drm/tegra/dpaux.c +++ b/drivers/gpu/drm/tegra/dpaux.c @@ -719,6 +719,7 @@ int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output) unsigned long timeout; int err;
+ aux->drm_dev = output->connector.dev; err = drm_dp_aux_register(aux); if (err < 0) return err; diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index 59d1fb017da0..7e5e89305028 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -1069,6 +1069,7 @@ static int zynqmp_dp_aux_init(struct zynqmp_dp *dp)
dp->aux.name = "ZynqMP DP AUX"; dp->aux.dev = dp->dev; + dp->aux.drm_dev = dp->drm; dp->aux.transfer = zynqmp_dp_aux_transfer;
return drm_dp_aux_register(&dp->aux); diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 1e85c2021f2f..95efe37ea9ca 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1840,6 +1840,8 @@ struct drm_dp_aux_cec { * @name: user-visible name of this AUX channel and the I2C-over-AUX adapter * @ddc: I2C adapter that can be used for I2C-over-AUX communication * @dev: pointer to struct device that is the parent for this AUX channel + * @drm_dev: pointer to the &drm_device that owns this AUX channel. Beware, this + * may be %NULL before drm_dp_aux_register() has been called. * @crtc: backpointer to the crtc that is currently using this AUX channel * @hw_mutex: internal mutex used for locking transfers * @crc_work: worker that captures CRCs for each frame @@ -1847,7 +1849,11 @@ struct drm_dp_aux_cec { * @transfer: transfers a message representing a single AUX transaction * * The @dev field should be set to a pointer to the device that implements the - * AUX channel. + * AUX channel. As well, the @drm_dev field should be set to the &drm_device + * that will be using this AUX channel as early as possible. For many graphics + * drivers this should happen before drm_dp_aux_init(), however it's perfectly + * fine to set this field later so long as it's assigned before calling + * drm_dp_aux_register(). * * The @name field may be used to specify the name of the I2C adapter. If set to * %NULL, dev_name() of @dev will be used. @@ -1879,6 +1885,7 @@ struct drm_dp_aux { const char *name; struct i2c_adapter ddc; struct device *dev; + struct drm_device *drm_dev; struct drm_crtc *crtc; struct mutex hw_mutex; struct work_struct crc_work;