Re: [PATCH v2] drm/amd/display: Add Debugfs Entry to Force in SST Sequence

[Aurabindo Pillai]

Reviewed-by: Aurabindo Pillai <aurabindo.pil...@amd.com>

On 12/7/21 2:57 PM, Fangzhi Zuo wrote:

It is to force SST sequence in MST capable receiver.

Signed-off-by: Fangzhi Zuo <jerry....@amd.com>
---
  .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 26 +++++++++++++++++++
  1 file changed, 26 insertions(+)

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 31c05eb5c64a..1779c7daaf72 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
@@ -3237,6 +3237,30 @@ static int disable_hpd_get(void *data, u64 *val)
  DEFINE_DEBUGFS_ATTRIBUTE(disable_hpd_ops, disable_hpd_get,
                         disable_hpd_set, "%llu\n");

+/*

+ * Force sst sequence in mst capable receiver.
+ * Example usage: echo 1 > 
/sys/kernel/debug/dri/0/amdgpu_dm_dp_set_mst_en_for_sst
+ */
+static int dp_force_sst_set(void *data, u64 val)
+{
+       struct amdgpu_device *adev = data;
+
+       adev->dm.dc->debug.set_mst_en_for_sst = val;
+
+       return 0;
+}
+
+static int dp_force_sst_get(void *data, u64 *val)
+{
+       struct amdgpu_device *adev = data;
+
+       *val = adev->dm.dc->debug.set_mst_en_for_sst;
+
+       return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(dp_set_mst_en_for_sst_ops, dp_force_sst_get,
+                        dp_force_sst_set, "%llu\n");
+
  /*
   * Sets the DC visual confirm debug option from the given string.
   * Example usage: echo 1 > /sys/kernel/debug/dri/0/amdgpu_visual_confirm
@@ -3346,6 +3370,8 @@ void dtn_debugfs_init(struct amdgpu_device *adev)
                            adev, &mst_topo_fops);
        debugfs_create_file("amdgpu_dm_dtn_log", 0644, root, adev,
                            &dtn_log_fops);
+       debugfs_create_file("amdgpu_dm_dp_set_mst_en_for_sst", 0644, root, adev,
+                               &dp_set_mst_en_for_sst_ops);

debugfs_create_file_unsafe("amdgpu_dm_visual_confirm", 0644, root, adev,

                                   &visual_confirm_fops);