On 4/11/2022 4:49 PM, Dmitry Baryshkov wrote:

Add calls to drm_bridge_add()/drm_bridge_remove() DRM bridges created by the driver. This fixes the following warning.

WARNING: CPU: 0 PID: 1 at kernel/locking/mutex.c:579 __mutex_lock+0x840/0x9f4 DEBUG_LOCKS_WARN_ON(lock->magic != lock) Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc1-00002-g3054695a0d27-dirty #55 Hardware name: Generic DT based system unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x58/0x70 dump_stack_lvl from __warn+0xc8/0x1e8 __warn from warn_slowpath_fmt+0x78/0xa8 warn_slowpath_fmt from __mutex_lock+0x840/0x9f4 __mutex_lock from mutex_lock_nested+0x1c/0x24 mutex_lock_nested from drm_bridge_hpd_enable+0x2c/0x84 drm_bridge_hpd_enable from msm_hdmi_modeset_init+0xc0/0x21c msm_hdmi_modeset_init from mdp4_kms_init+0x53c/0x90c mdp4_kms_init from msm_drm_bind+0x514/0x698 msm_drm_bind from try_to_bring_up_aggregate_device+0x160/0x1bc try_to_bring_up_aggregate_device from component_master_add_with_match+0xc4/0xf8 component_master_add_with_match from msm_pdev_probe+0x274/0x350 msm_pdev_probe from platform_probe+0x5c/0xbc platform_probe from really_probe.part.0+0x9c/0x290 really_probe.part.0 from __driver_probe_device+0xa8/0x13c __driver_probe_device from driver_probe_device+0x34/0x10c driver_probe_device from __driver_attach+0xbc/0x178 __driver_attach from bus_for_each_dev+0x74/0xc0 bus_for_each_dev from bus_add_driver+0x160/0x1e4 bus_add_driver from driver_register+0x88/0x118 driver_register from do_one_initcall+0x6c/0x334 do_one_initcall from kernel_init_freeable+0x1bc/0x220 kernel_init_freeable from kernel_init+0x18/0x12c kernel_init from ret_from_fork+0x14/0x2c

Fixes: 3d3f8b1f8b62 ("drm/bridge: make bridge registration independent of drm flow") Reported-by: kernel test robot lkp@intel.com Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org

Reviewed-by: Abhinav Kumar quic_abhinavk@quicinc.com

---

Changes since v1:

• Dropped drm_bridge_detach() call, it is not necessary, also it breaks compilation if MSM DRM is built as module.

---

drivers/gpu/drm/msm/dp/dp_drm.c | 4 ++++ drivers/gpu/drm/msm/dsi/dsi_manager.c | 3 +++ drivers/gpu/drm/msm/hdmi/hdmi_bridge.c | 3 +++ drivers/gpu/drm/msm/msm_drv.c | 3 +++ 4 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c index 80f59cf99089..262744914f97 100644 --- a/drivers/gpu/drm/msm/dp/dp_drm.c +++ b/drivers/gpu/drm/msm/dp/dp_drm.c @@ -230,9 +230,13 @@ struct drm_bridge *msm_dp_bridge_init(struct msm_dp *dp_display, struct drm_devi bridge->funcs = &dp_bridge_ops; bridge->encoder = encoder;

• drm_bridge_add(bridge);
• rc = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR); if (rc) { DRM_ERROR("failed to attach bridge, rc=%d\n", rc);

• drm_bridge_remove(bridge);
  

• return ERR_PTR(rc); }

diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c index 9f6af0f0fe00..1db93e562fe6 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -665,6 +665,8 @@ struct drm_bridge *msm_dsi_manager_bridge_init(u8 id) bridge = &dsi_bridge->base; bridge->funcs = &dsi_mgr_bridge_funcs;

• drm_bridge_add(bridge);
• ret = drm_bridge_attach(encoder, bridge, NULL, 0); if (ret) goto fail;

@@ -735,6 +737,7 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)

void msm_dsi_manager_bridge_destroy(struct drm_bridge *bridge) {

• drm_bridge_remove(bridge); }

  int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg)

diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c index 10ebe2089cb6..97c24010c4d1 100644 --- a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c +++ b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c @@ -15,6 +15,7 @@ void msm_hdmi_bridge_destroy(struct drm_bridge *bridge) struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);

msm_hdmi_hpd_disable(hdmi_bridge);

• drm_bridge_remove(bridge); }

  static void msm_hdmi_power_on(struct drm_bridge *bridge)

@@ -349,6 +350,8 @@ struct drm_bridge *msm_hdmi_bridge_init(struct hdmi *hdmi) DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID;

• drm_bridge_add(bridge);
• ret = drm_bridge_attach(hdmi->encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR); if (ret) goto fail;

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index 2905b82a9de3..d8f2c8838a7f 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -232,6 +232,9 @@ static int msm_drm_uninit(struct device *dev)

drm_mode_config_cleanup(ddev);

• for (i = 0; i < priv->num_bridges; i++)

• drm_bridge_remove(priv->bridges[i]);
  

• pm_runtime_get_sync(dev); msm_irq_uninstall(ddev); pm_runtime_put_sync(dev);