From 15c735e7990fdabb466a3341b6b2dfefd987127e Mon Sep 17 00:00:00 2001 From: Wayne Lin Date: Tue, 31 May 2022 17:46:24 +0800 Subject: [PATCH] drm/amd/display: Grab dc_lock before detecting link [Why & How] There is chance we change dc state while calling dc_link_detect(). As the result of that, grab the dm.dc_lock before detecting link. Reviewed-by: Hersen Wu Acked-by: Solomon Chiu Signed-off-by: Wayne Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 85 ++++++++++++++-------- .../drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 11 ++- 2 files changed, 63 insertions(+), 33 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 ea22bda..081d28a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2756,10 +2756,13 @@ static int dm_resume(void *handle) if (!dc_link_detect_sink(aconnector->dc_link, &new_connection_type)) DRM_ERROR("KMS: Failed to detect connector\n"); - if (aconnector->base.force && new_connection_type == dc_connection_none) + if (aconnector->base.force && new_connection_type == dc_connection_none) { emulated_link_detect(aconnector->dc_link); - else + } else { + mutex_lock(&dm->dc_lock); dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD); + mutex_unlock(&dm->dc_lock); + } if (aconnector->fake_enable && aconnector->dc_link->local_sink) aconnector->fake_enable = false; @@ -3090,6 +3093,7 @@ static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector) #ifdef CONFIG_DRM_AMD_DC_HDCP struct dm_connector_state *dm_con_state = to_dm_connector_state(connector->state); #endif + bool ret = false; if (adev->dm.disable_hpd_irq) return; @@ -3121,16 +3125,20 @@ static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector) if (aconnector->base.force == DRM_FORCE_UNSPECIFIED) drm_kms_helper_connector_hotplug_event(connector); + } else { + mutex_lock(&adev->dm.dc_lock); + ret = dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD); + mutex_unlock(&adev->dm.dc_lock); + if (ret) { + amdgpu_dm_update_connector_after_detect(aconnector); - } else if (dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD)) { - amdgpu_dm_update_connector_after_detect(aconnector); - - drm_modeset_lock_all(dev); - dm_restore_drm_connector_state(dev, connector); - drm_modeset_unlock_all(dev); + drm_modeset_lock_all(dev); + dm_restore_drm_connector_state(dev, connector); + drm_modeset_unlock_all(dev); - if (aconnector->base.force == DRM_FORCE_UNSPECIFIED) - drm_kms_helper_connector_hotplug_event(connector); + if (aconnector->base.force == DRM_FORCE_UNSPECIFIED) + drm_kms_helper_connector_hotplug_event(connector); + } } mutex_unlock(&aconnector->hpd_lock); @@ -3325,19 +3333,25 @@ out: drm_modeset_unlock_all(dev); drm_kms_helper_connector_hotplug_event(connector); - } else if (dc_link_detect(dc_link, DETECT_REASON_HPDRX)) { + } else { + bool ret = false; - if (aconnector->fake_enable) - aconnector->fake_enable = false; + mutex_lock(&adev->dm.dc_lock); + ret = dc_link_detect(dc_link, DETECT_REASON_HPDRX); + mutex_unlock(&adev->dm.dc_lock); - amdgpu_dm_update_connector_after_detect(aconnector); + if (ret) { + if (aconnector->fake_enable) + aconnector->fake_enable = false; + amdgpu_dm_update_connector_after_detect(aconnector); - drm_modeset_lock_all(dev); - dm_restore_drm_connector_state(dev, connector); - drm_modeset_unlock_all(dev); + drm_modeset_lock_all(dev); + dm_restore_drm_connector_state(dev, connector); + drm_modeset_unlock_all(dev); - drm_kms_helper_connector_hotplug_event(connector); + drm_kms_helper_connector_hotplug_event(connector); + } } } #ifdef CONFIG_DRM_AMD_DC_HDCP @@ -4342,23 +4356,30 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev) if (aconnector->base.force && new_connection_type == dc_connection_none) { emulated_link_detect(link); amdgpu_dm_update_connector_after_detect(aconnector); + } else { + bool ret = false; - } else if (dc_link_detect(link, DETECT_REASON_BOOT)) { - amdgpu_dm_update_connector_after_detect(aconnector); - register_backlight_device(dm, link); - if (dm->num_of_edps) - update_connector_ext_caps(aconnector); - if (psr_feature_enabled) - amdgpu_dm_set_psr_caps(link); - - /* TODO: Fix vblank control helpers to delay PSR entry to allow this when - * PSR is also supported. - */ - if (link->psr_settings.psr_feature_enabled) - adev_to_drm(adev)->vblank_disable_immediate = false; - } + mutex_lock(&dm->dc_lock); + ret = dc_link_detect(link, DETECT_REASON_BOOT); + mutex_unlock(&dm->dc_lock); + if (ret) { + amdgpu_dm_update_connector_after_detect(aconnector); + register_backlight_device(dm, link); + if (dm->num_of_edps) + update_connector_ext_caps(aconnector); + + if (psr_feature_enabled) + amdgpu_dm_set_psr_caps(link); + + /* TODO: Fix vblank control helpers to delay PSR entry to allow this when + * PSR is also supported. + */ + if (link->psr_settings.psr_feature_enabled) + adev_to_drm(adev)->vblank_disable_immediate = false; + } + } } /* Software is initialized. Now we can register interrupt handlers. */ diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c index 4d5824e..49bdcbf 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c @@ -1239,12 +1239,14 @@ static ssize_t trigger_hotplug(struct file *f, const char __user *buf, struct drm_connector *connector = &aconnector->base; struct dc_link *link = NULL; struct drm_device *dev = connector->dev; + struct amdgpu_device *adev = drm_to_adev(dev); enum dc_connection_type new_connection_type = dc_connection_none; char *wr_buf = NULL; uint32_t wr_buf_size = 42; int max_param_num = 1; long param[1] = {0}; uint8_t param_nums = 0; + bool ret = false; if (!aconnector || !aconnector->dc_link) return -EINVAL; @@ -1280,7 +1282,11 @@ static ssize_t trigger_hotplug(struct file *f, const char __user *buf, new_connection_type != dc_connection_none) goto unlock; - if (!dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD)) + mutex_lock(&adev->dm.dc_lock); + ret = dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD); + mutex_unlock(&adev->dm.dc_lock); + + if (!ret) goto unlock; amdgpu_dm_update_connector_after_detect(aconnector); @@ -3302,7 +3308,10 @@ static int trigger_hpd_mst_set(void *data, u64 val) aconnector = to_amdgpu_dm_connector(connector); if (aconnector->dc_link->type == dc_connection_mst_branch && aconnector->mst_mgr.aux) { + mutex_lock(&adev->dm.dc_lock); dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD); + mutex_unlock(&adev->dm.dc_lock); + drm_dp_mst_topology_mgr_set_mst(&aconnector->mst_mgr, true); } } -- 2.7.4