[PATCH 14/21] drm/amd/display: Grab dc_lock before detecting link
Solomon Chiu
solomon.chiu at amd.com
Tue Jul 12 15:38:55 UTC 2022
From: Wayne Lin <Wayne.Lin at amd.com>
[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 <hersen.wu at amd.com>
Acked-by: Solomon Chiu <solomon.chiu at amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin at amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler at amd.com>
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 85 ++++++++++++-------
.../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 de1c139ae279..000d34a7b6b4 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2716,10 +2716,13 @@ 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;
@@ -3050,6 +3053,7 @@ 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;
@@ -3081,16 +3085,20 @@ 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);
@@ -3285,19 +3293,25 @@ static void handle_hpd_rx_irq(void *param)
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
@@ -4302,23 +4316,30 @@ 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 01c98ad06cf0..e0646db6fdbf 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
@@ -1243,12 +1243,14 @@ 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;
@@ -1284,7 +1286,11 @@ 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);
@@ -3306,7 +3312,10 @@ 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);
}
}
--
2.25.1
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