[PATCH v2 07/21] drm/i915/dp: Recheck link state after modeset

Imre Deak
2024-05-20T18:58:40Z

Recheck the link state after a passing link training, with a 2 sec delay
to account for cases where the link goes bad following the link training
and the sink doesn't report this via an HPD IRQ.

The delayed work added here will be also used by a later patch after a
failed link training to try to retrain the link with unchanged link
params before reducing the link params.

v2: Don't flush an uninitialized delayed work (on HDMI-only DDI ports).
v3: Add the work to intel_digital_port instead of intel_dp.

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
drivers/gpu/drm/i915/display/g4x_dp.c | 7 ++++
drivers/gpu/drm/i915/display/intel_ddi.c | 34 +++++++++++++++++++
drivers/gpu/drm/i915/display/intel_ddi.h | 4 +++
.../drm/i915/display/intel_display_types.h | 3 ++
drivers/gpu/drm/i915/display/intel_dp.c | 1 +
.../drm/i915/display/intel_dp_link_training.c | 12 +++++--
6 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/g4x_dp.c b/drivers/gpu/drm/i915/display/g4x_dp.c
index 06ec04e667e32..4363e32a834df 100644
--- a/drivers/gpu/drm/i915/display/g4x_dp.c
+++ b/drivers/gpu/drm/i915/display/g4x_dp.c
@@ -20,6 +20,7 @@
#include "intel_dp_aux.h"
#include "intel_dp_link_training.h"
#include "intel_dpio_phy.h"
+#include "intel_ddi.h"
#include "intel_fifo_underrun.h"
#include "intel_hdmi.h"
#include "intel_hotplug.h"
@@ -1241,6 +1242,10 @@ static bool ilk_digital_port_connected(struct intel_encoder *encoder)

static void intel_dp_encoder_destroy(struct drm_encoder *encoder)
{
+ struct intel_digital_port *dig_port = enc_to_dig_port(to_intel_encoder(encoder));
+
+ intel_ddi_flush_link_check_work(dig_port);
+
intel_dp_encoder_flush_work(encoder);

drm_encoder_cleanup(encoder);
@@ -1309,6 +1314,8 @@ bool g4x_dp_init(struct drm_i915_private *dev_priv,

dig_port->aux_ch = AUX_CH_NONE;

+ intel_ddi_init_link_check_work(dig_port);
+
intel_connector = intel_connector_alloc();
if (!intel_connector)
goto err_connector_alloc;
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 170ba01786cf8..86358ec27e685 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -4360,6 +4360,7 @@ static void intel_ddi_encoder_destroy(struct drm_encoder *encoder)
struct drm_i915_private *i915 = to_i915(encoder->dev);
struct intel_digital_port *dig_port = enc_to_dig_port(to_intel_encoder(encoder));

+ intel_ddi_flush_link_check_work(dig_port);
intel_dp_encoder_flush_work(encoder);
if (intel_encoder_is_tc(&dig_port->base))
intel_tc_port_cleanup(dig_port);
@@ -4441,6 +4442,37 @@ intel_ddi_init_dp_connector(struct intel_digital_port *dig_port)
return connector;
}

+static void intel_ddi_link_check_work_fn(struct work_struct *work)
+{
+ struct intel_digital_port *dig_port =
+ container_of(work, typeof(*dig_port), check_link_work.work);
+ struct intel_encoder *encoder = &dig_port->base;
+ struct drm_modeset_acquire_ctx ctx;
+ int ret;
+
+ intel_modeset_lock_ctx_retry(&ctx, NULL, 0, ret)
+ if (dig_port->dp.attached_connector)
+ ret = intel_dp_retrain_link(encoder, &ctx);
+}
+
+void intel_ddi_init_link_check_work(struct intel_digital_port *dig_port)
+{
+ INIT_DELAYED_WORK(&dig_port->check_link_work, intel_ddi_link_check_work_fn);
+}
+
+void intel_ddi_flush_link_check_work(struct intel_digital_port *dig_port)
+{
+ cancel_delayed_work_sync(&dig_port->check_link_work);
+}
+
+void intel_ddi_queue_link_check(struct intel_digital_port *dig_port, int delay_ms)
+{
+ struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+
+ mod_delayed_work(i915->unordered_wq,
+ &dig_port->check_link_work, msecs_to_jiffies(delay_ms));
+}
+
static int intel_hdmi_reset_link(struct intel_encoder *encoder,
struct drm_modeset_acquire_ctx *ctx)
{
@@ -4911,6 +4943,8 @@ void intel_ddi_init(struct drm_i915_private *dev_priv,

dig_port->aux_ch = AUX_CH_NONE;

+ intel_ddi_init_link_check_work(dig_port);
+
encoder = &dig_port->base;
encoder->devdata = devdata;

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.h b/drivers/gpu/drm/i915/display/intel_ddi.h
index 434de7196875a..b67714483f3cc 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.h
+++ b/drivers/gpu/drm/i915/display/intel_ddi.h
@@ -15,6 +15,7 @@ struct intel_bios_encoder_data;
struct intel_connector;
struct intel_crtc;
struct intel_crtc_state;
+struct intel_digital_port;
struct intel_dp;
struct intel_dpll_hw_state;
struct intel_encoder;
@@ -53,6 +54,9 @@ void hsw_prepare_dp_ddi_buffers(struct intel_encoder *encoder,
const struct intel_crtc_state *crtc_state);
void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
enum port port);
+void intel_ddi_init_link_check_work(struct intel_digital_port *dig_port);
+void intel_ddi_flush_link_check_work(struct intel_digital_port *dig_port);
+void intel_ddi_queue_link_check(struct intel_digital_port *dig_port, int delay_ms);
void intel_ddi_init(struct drm_i915_private *dev_priv,
const struct intel_bios_encoder_data *devdata);
bool intel_ddi_get_hw_state(struct intel_encoder *encoder, enum pipe *pipe);
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 1e44a23ca2125..9317c1ae04efe 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1880,6 +1880,9 @@ struct intel_digital_port {

struct intel_tc_port *tc;

+ /* Check and recover a bad link status on DP and HDMI ports. */
+ struct delayed_work check_link_work;
+
/* protects num_hdcp_streams reference count, hdcp_port_data and hdcp_auth_status */
struct mutex hdcp_mutex;
/* the number of pipes using HDCP signalling out of this port */
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 120f7b420807b..8da277f0c2735 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -75,6 +75,7 @@
#include "intel_hotplug_irq.h"
#include "intel_lspcon.h"
#include "intel_lvds.h"
+#include "intel_modeset_lock.h"
#include "intel_panel.h"
#include "intel_pch_display.h"
#include "intel_pps.h"
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
index edc970036866a..ad1fbb150ff90 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -25,6 +25,7 @@
#include "intel_display_types.h"
#include "intel_dp.h"
#include "intel_dp_link_training.h"
+#include "intel_ddi.h"
#include "intel_panel.h"

#define LT_MSG_PREFIX "[CONNECTOR:%d:%s][ENCODER:%d:%s][%s] "
@@ -1464,6 +1465,7 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp,
const struct intel_crtc_state *crtc_state)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+ struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
bool passed;

/*
@@ -1483,6 +1485,11 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp,
else
passed = intel_dp_link_train_all_phys(intel_dp, crtc_state, lttpr_count);

+ if (passed) {
+ intel_ddi_queue_link_check(dig_port, 2000);
+ return;
+ }
+
/*
* Ignore the link failure in CI
*
@@ -1495,13 +1502,12 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp,
* For test cases which rely on the link training or processing of HPDs
* ignore_long_hpd flag can unset from the testcase.
*/
- if (!passed && i915->display.hotplug.ignore_long_hpd) {
+ if (i915->display.hotplug.ignore_long_hpd) {
lt_dbg(intel_dp, DP_PHY_DPRX, "Ignore the link failure\n");
return;
}

- if (!passed)
- intel_dp_schedule_fallback_link_training(intel_dp, crtc_state);
+ intel_dp_schedule_fallback_link_training(intel_dp, crtc_state);
}

void intel_dp_128b132b_sdp_crc16(struct intel_dp *intel_dp,
--
2.43.3