[PATCH v3] drm/msm/dp: fix connect/disconnect handled at irq_hpd

From: Kuogee Hsieh
Date: Wed Nov 18 2020 - 16:01:27 EST


Some usb type-c dongle use irq_hpd request to perform device connection
and disconnection. This patch add handling of both connection and
disconnection are based on the state of hpd_state and sink_count.

Changes in V2:
-- add dp_display_handle_port_ststus_changed()
-- fix kernel test robot complaint

Changes in V3:
-- add encoder_mode_set into struct dp_display_private

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Fixes: 26b8d66a399e ("drm/msm/dp: promote irq_hpd handle to handle link training correctly")
Tested-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_display.c | 92 ++++++++++++++++++++++---------------
1 file changed, 55 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index e9cb878..6e971d5 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -102,6 +102,8 @@ struct dp_display_private {
struct dp_display_mode dp_mode;
struct msm_dp dp_display;

+ bool encoder_mode_set;
+
/* wait for audio signaling */
struct completion audio_comp;

@@ -279,13 +281,24 @@ static void dp_display_send_hpd_event(struct msm_dp *dp_display)
drm_helper_hpd_irq_event(connector->dev);
}

-static int dp_display_send_hpd_notification(struct dp_display_private *dp,
- bool hpd)
+
+static void dp_display_set_encoder_mode(struct dp_display_private *dp)
{
- static bool encoder_mode_set;
struct msm_drm_private *priv = dp->dp_display.drm_dev->dev_private;
struct msm_kms *kms = priv->kms;

+ if (!dp->encoder_mode_set && dp->dp_display.encoder &&
+ kms->funcs->set_encoder_mode) {
+ kms->funcs->set_encoder_mode(kms,
+ dp->dp_display.encoder, false);
+
+ dp->encoder_mode_set = true;
+ }
+}
+
+static int dp_display_send_hpd_notification(struct dp_display_private *dp,
+ bool hpd)
+{
if ((hpd && dp->dp_display.is_connected) ||
(!hpd && !dp->dp_display.is_connected)) {
DRM_DEBUG_DP("HPD already %s\n", (hpd ? "on" : "off"));
@@ -298,15 +311,6 @@ static int dp_display_send_hpd_notification(struct dp_display_private *dp,

dp->dp_display.is_connected = hpd;

- if (dp->dp_display.is_connected && dp->dp_display.encoder
- && !encoder_mode_set
- && kms->funcs->set_encoder_mode) {
- kms->funcs->set_encoder_mode(kms,
- dp->dp_display.encoder, false);
- DRM_DEBUG_DP("set_encoder_mode() Completed\n");
- encoder_mode_set = true;
- }
-
dp_display_send_hpd_event(&dp->dp_display);

return 0;
@@ -342,7 +346,6 @@ static int dp_display_process_hpd_high(struct dp_display_private *dp)

dp_add_event(dp, EV_USER_NOTIFICATION, true, 0);

-
end:
return rc;
}
@@ -359,6 +362,8 @@ static void dp_display_host_init(struct dp_display_private *dp)
if (dp->usbpd->orientation == ORIENTATION_CC2)
flip = true;

+ dp_display_set_encoder_mode(dp);
+
dp_power_init(dp->power, flip);
dp_ctrl_host_init(dp->ctrl, flip);
dp_aux_init(dp->aux);
@@ -442,24 +447,42 @@ static void dp_display_handle_video_request(struct dp_display_private *dp)
}
}

-static int dp_display_handle_irq_hpd(struct dp_display_private *dp)
+static int dp_display_handle_port_ststus_changed(struct dp_display_private *dp)
{
- u32 sink_request;
-
- sink_request = dp->link->sink_request;
+ int rc = 0;

- if (sink_request & DS_PORT_STATUS_CHANGED) {
- if (dp_display_is_sink_count_zero(dp)) {
- DRM_DEBUG_DP("sink count is zero, nothing to do\n");
- return -ENOTCONN;
+ if (dp_display_is_sink_count_zero(dp)) {
+ DRM_DEBUG_DP("sink count is zero, nothing to do\n");
+ if (dp->hpd_state != ST_DISCONNECTED) {
+ dp->hpd_state = ST_DISCONNECT_PENDING;
+ dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);
+ }
+ } else {
+ if (dp->hpd_state == ST_DISCONNECTED) {
+ dp->hpd_state = ST_CONNECT_PENDING;
+ rc = dp_display_process_hpd_high(dp);
+ if (rc)
+ dp->hpd_state = ST_DISCONNECTED;
}
+ }
+
+ return rc;
+}
+
+static int dp_display_handle_irq_hpd(struct dp_display_private *dp)
+{
+ u32 sink_request = dp->link->sink_request;

- return dp_display_process_hpd_high(dp);
+ if (dp->hpd_state == ST_DISCONNECTED) {
+ if (sink_request & DP_LINK_STATUS_UPDATED) {
+ DRM_ERROR("Disconnected, no DP_LINK_STATUS_UPDATED\n");
+ return -EINVAL;
+ }
}

dp_ctrl_handle_sink_request(dp->ctrl);

- if (dp->link->sink_request & DP_TEST_LINK_VIDEO_PATTERN)
+ if (sink_request & DP_TEST_LINK_VIDEO_PATTERN)
dp_display_handle_video_request(dp);

return 0;
@@ -490,19 +513,10 @@ static int dp_display_usbpd_attention_cb(struct device *dev)
rc = dp_link_process_request(dp->link);
if (!rc) {
sink_request = dp->link->sink_request;
- if (sink_request & DS_PORT_STATUS_CHANGED) {
- /* same as unplugged */
- hpd->hpd_high = 0;
- dp->hpd_state = ST_DISCONNECT_PENDING;
- dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);
- }
-
- rc = dp_display_handle_irq_hpd(dp);
-
- if (!rc && (sink_request & DS_PORT_STATUS_CHANGED)) {
- hpd->hpd_high = 1;
- dp->hpd_state = ST_CONNECT_PENDING;
- }
+ if (sink_request & DS_PORT_STATUS_CHANGED)
+ rc = dp_display_handle_port_ststus_changed(dp);
+ else
+ rc = dp_display_handle_irq_hpd(dp);
}

return rc;
@@ -668,6 +682,7 @@ static int dp_disconnect_pending_timeout(struct dp_display_private *dp, u32 data
static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
{
u32 state;
+ int ret;

mutex_lock(&dp->event_mutex);

@@ -678,7 +693,10 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
return 0;
}

- dp_display_usbpd_attention_cb(&dp->pdev->dev);
+ ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
+ if (ret == -ECONNRESET) { /* cable unplugged */
+ dp->core_initialized = false;
+ }

mutex_unlock(&dp->event_mutex);

--
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