From 88d65a93d64a41800052e1759fd6c5c92b91d9dc Mon Sep 17 00:00:00 2001
From: Jimmy Kizito <Jimmy.Kizito@amd.com>
Date: Wed, 25 Aug 2021 21:26:33 -0400
Subject: drm/amd/display: Add debug flags for USB4 DP link training.
Git-commit: 6aa8d42c6674461720bb826a5f1cdcdfe85253f1
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
[Why & How]
Additional debug flags that can be useful for testing USB4 DP
link training.
Add flags:
- 0x2 : Forces USB4 DP link to non-LTTPR mode
- 0x4 : Extends status read intervals to about 60s.
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Wayne Lin <Wayne.Lin@amd.com>
Acked-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 6 ++++++
drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c | 6 ++++++
drivers/gpu/drm/amd/display/dc/dc.h | 4 +++-
drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h | 3 +++
4 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 56aaab22fa42..54662d74c65a 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -4527,6 +4527,12 @@ bool dp_retrieve_lttpr_cap(struct dc_link *link)
else
link->lttpr_mode = LTTPR_MODE_NON_TRANSPARENT;
}
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+ /* Check DP tunnel LTTPR mode debug option. */
+ if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
+ link->dc->debug.dpia_debug.bits.force_non_lttpr)
+ link->lttpr_mode = LTTPR_MODE_NON_LTTPR;
+#endif
if (link->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT || link->lttpr_mode == LTTPR_MODE_TRANSPARENT) {
/* By reading LTTPR capability, RX assumes that we will enable
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c
index bb2efce67f0d..9c620b61f64e 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c
@@ -534,6 +534,12 @@ static uint32_t dpia_get_eq_aux_rd_interval(const struct dc_link *link,
dp_translate_training_aux_read_interval(
link->dpcd_caps.lttpr_caps.aux_rd_interval[hop - 1]);
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+ /* Check debug option for extending aux read interval. */
+ if (link->dc->debug.dpia_debug.bits.extend_aux_rd_interval)
+ wait_time_microsec = DPIA_DEBUG_EXTENDED_AUX_RD_INTERVAL_US;
+#endif
+
return wait_time_microsec;
}
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 5185c2d512f7..dd995905b0cb 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -499,7 +499,9 @@ union root_clock_optimization_options {
union dpia_debug_options {
struct {
uint32_t disable_dpia:1;
- uint32_t reserved:31;
+ uint32_t force_non_lttpr:1;
+ uint32_t extend_aux_rd_interval:1;
+ uint32_t reserved:29;
} bits;
uint32_t raw;
};
diff --git a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h
index 28e68be41123..974d703e3771 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dpia.h
@@ -35,6 +35,9 @@ struct dc_link_settings;
/* The approximate time (us) it takes to transmit 9 USB4 DP clock sync packets. */
#define DPIA_CLK_SYNC_DELAY 16000
+/* Extend interval between training status checks for manual testing. */
+#define DPIA_DEBUG_EXTENDED_AUX_RD_INTERVAL_US 60000000
+
/** @note Can remove once DP tunneling registers in upstream include/drm/drm_dp_helper.h */
/* DPCD DP Tunneling over USB4 */
#define DP_TUNNELING_CAPABILITIES_SUPPORT 0xe000d
--
2.38.1