drm/amd/display: Add a new dcdebugmask to allow skip detection LT

Under specific embedded scenarios, we might still use DP interface
rather than eDP interface. Under such case, detection link training
is unnecessary.

Add a new dcdebugmask value that can be used to skip the detection LT

Reviewed-by: Tom Chung <chiahsuan.chung@amd.com>
Link: https://lore.kernel.org/amd-gfx/20250521063934.2111323-1-Wayne.Lin@amd.com/
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 4b4e9241619f1504b62d7dca77760a6a949eb69c..2bb347771aa14e18cea8f5a84a549e1965f8ead0 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2020,6 +2020,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
        if (amdgpu_dc_debug_mask & DC_HDCP_LC_ENABLE_SW_FALLBACK)
                adev->dm.dc->debug.hdcp_lc_enable_sw_fallback = true;
 
+       if (amdgpu_dc_debug_mask & DC_SKIP_DETECTION_LT)
+               adev->dm.dc->debug.skip_detection_link_training = true;
+
        adev->dm.dc->debug.visual_confirm = amdgpu_dc_visual_confirm;
 
        /* TODO: Remove after DP2 receiver gets proper support of Cable ID feature */

diff --git a/drivers/gpu/drm/amd/include/amd_shared.h b/drivers/gpu/drm/amd/include/amd_shared.h
index c8eccee9b023b6f9f9989f4a81ab337fdfb93283..31de36c9156f7315d1311a55482b4436a96f76c5 100644 (file)
--- a/drivers/gpu/drm/amd/include/amd_shared.h
+++ b/drivers/gpu/drm/amd/include/amd_shared.h
@@ -370,6 +370,11 @@ enum DC_DEBUG_MASK {
         * path failure, retry using legacy SW path.
         */
        DC_HDCP_LC_ENABLE_SW_FALLBACK = 0x100000,
+
+       /**
+        * @DC_SKIP_DETECTION_LT: If set, skip detection link training
+        */
+       DC_SKIP_DETECTION_LT = 0x200000,
 };
 
 enum amd_dpm_forced_level;