2021-01-13 19:03:34

by Kuogee Hsieh

[permalink] [raw]
Subject: [PATCH v2 2/2] drm/msm/dp: unplug interrupt missed after irq_hpd handler

There is HPD unplug interrupts missed at scenario of an irq_hpd
followed by unplug interrupts with around 10 ms in between.
Since both AUX_SW_RESET and DP_SW_RESET clear pending HPD interrupts,
irq_hpd handler should not issues either aux or sw reset to avoid
following unplug interrupt be cleared accidentally. This patch
also postpone handling of irq_hpd until connected state if it
happened at connection pending state.

Changes in V2:
-- add postpone handling of irq_hpd until connected state
-- check DP_TRAINING_1 instead of DP_TRAINING_NONE

Signed-off-by: Kuogee Hsieh <[email protected]>
---
drivers/gpu/drm/msm/dp/dp_aux.c | 7 -------
drivers/gpu/drm/msm/dp/dp_catalog.c | 24 ++++++++++++++++++++++++
drivers/gpu/drm/msm/dp/dp_ctrl.c | 15 ++++++++++-----
drivers/gpu/drm/msm/dp/dp_display.c | 7 +++++++
4 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
index 19b35ae..1c6e1d2 100644
--- a/drivers/gpu/drm/msm/dp/dp_aux.c
+++ b/drivers/gpu/drm/msm/dp/dp_aux.c
@@ -336,7 +336,6 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
ssize_t ret;
int const aux_cmd_native_max = 16;
int const aux_cmd_i2c_max = 128;
- int const retry_count = 5;
struct dp_aux_private *aux = container_of(dp_aux,
struct dp_aux_private, dp_aux);

@@ -378,12 +377,6 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
ret = dp_aux_cmd_fifo_tx(aux, msg);

if (ret < 0) {
- if (aux->native) {
- aux->retry_cnt++;
- if (!(aux->retry_cnt % retry_count))
- dp_catalog_aux_update_cfg(aux->catalog);
- dp_catalog_aux_reset(aux->catalog);
- }
usleep_range(400, 500); /* at least 400us to next try */
goto unlock_exit;
}
diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
index 44f0c57..b1a9b1b 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.c
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
@@ -190,6 +190,18 @@ int dp_catalog_aux_clear_hw_interrupts(struct dp_catalog *dp_catalog)
return 0;
}

+/**
+ * dp_catalog_aux_reset() - reset AUX controller
+ *
+ * @aux: DP catalog structure
+ *
+ * return: void
+ *
+ * This function reset AUX controller
+ *
+ * NOTE: reset AUX controller will also clear any pending HPD related interrupts
+ *
+ */
void dp_catalog_aux_reset(struct dp_catalog *dp_catalog)
{
u32 aux_ctrl;
@@ -483,6 +495,18 @@ int dp_catalog_ctrl_set_pattern(struct dp_catalog *dp_catalog,
return 0;
}

+/**
+ * dp_catalog_ctrl_reset() - reset DP controller
+ *
+ * @dp_catalog: DP catalog structure
+ *
+ * return: void
+ *
+ * This function reset the DP controller
+ *
+ * NOTE: reset DP controller will also clear any pending HPD related interrupts
+ *
+ */
void dp_catalog_ctrl_reset(struct dp_catalog *dp_catalog)
{
u32 sw_reset;
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index e3462f5..5ac155d 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1296,7 +1296,8 @@ static int dp_ctrl_setup_main_link(struct dp_ctrl_private *ctrl,
* transitioned to PUSH_IDLE. In order to start transmitting
* a link training pattern, we have to first do soft reset.
*/
- dp_catalog_ctrl_reset(ctrl->catalog);
+ if (*training_step == DP_TRAINING_1)
+ dp_catalog_ctrl_reset(ctrl->catalog);

ret = dp_ctrl_link_train(ctrl, cr, training_step);

@@ -1491,15 +1492,18 @@ static int dp_ctrl_deinitialize_mainlink(struct dp_ctrl_private *ctrl)
return 0;
}

+static void dp_ctrl_link_idle_reset(struct dp_ctrl_private *ctrl)
+{
+ dp_ctrl_push_idle(&ctrl->dp_ctrl);
+ dp_catalog_ctrl_reset(ctrl->catalog);
+}
+
static int dp_ctrl_link_maintenance(struct dp_ctrl_private *ctrl)
{
int ret = 0;
struct dp_cr_status cr;
int training_step = DP_TRAINING_NONE;

- dp_ctrl_push_idle(&ctrl->dp_ctrl);
- dp_catalog_ctrl_reset(ctrl->catalog);
-
ctrl->dp_ctrl.pixel_rate = ctrl->panel->dp_mode.drm_mode.clock;

ret = dp_ctrl_setup_main_link(ctrl, &cr, &training_step);
@@ -1626,6 +1630,7 @@ void dp_ctrl_handle_sink_request(struct dp_ctrl *dp_ctrl)

if (sink_request & DP_TEST_LINK_TRAINING) {
dp_link_send_test_response(ctrl->link);
+ dp_ctrl_link_idle_reset(ctrl);
if (dp_ctrl_link_maintenance(ctrl)) {
DRM_ERROR("LM failed: TEST_LINK_TRAINING\n");
return;
@@ -1679,7 +1684,7 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
break;
}

- training_step = DP_TRAINING_NONE;
+ training_step = DP_TRAINING_1;
rc = dp_ctrl_setup_main_link(ctrl, &cr, &training_step);
if (rc == 0) {
/* training completed successfully */
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 6e971d5..3bc7ed2 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -693,6 +693,13 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
return 0;
}

+ if (state == ST_CONNECT_PENDING) {
+ /* wait until ST_CONNECTED */
+ dp_add_event(dp, EV_IRQ_HPD_INT, 0, 1); /* delay = 1 */
+ mutex_unlock(&dp->event_mutex);
+ return 0;
+ }
+
ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
if (ret == -ECONNRESET) { /* cable unplugged */
dp->core_initialized = false;
--
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