[PATCH 1/2] drm/msm/dp: postpone irq_hpd event during connection pending state

[Kuogee Hsieh]

irq_hpd event can only be executed at connected state. Therefore
irq_hpd event should be postponed if it happened at connection
pending state. This patch also make sure both link rate and lane
are valid before start link training.

Signed-off-by: Kuogee Hsieh <khs...@codeaurora.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c |  7 +++++++
 drivers/gpu/drm/msm/dp/dp_panel.c   | 12 +++++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

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;
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c 
b/drivers/gpu/drm/msm/dp/dp_panel.c
index 97dca3e..d1780bc 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -167,12 +167,18 @@ int dp_panel_read_sink_caps(struct dp_panel *dp_panel,
        panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
 
        rc = dp_panel_read_dpcd(dp_panel);
+       if (rc) {
+               DRM_ERROR("read dpcd failed %d\n", rc);
+               return rc;
+       }
+
        bw_code = drm_dp_link_rate_to_bw_code(dp_panel->link_info.rate);
-       if (rc || !is_link_rate_valid(bw_code) ||
+       if (!is_link_rate_valid(bw_code) ||
                        !is_lane_count_valid(dp_panel->link_info.num_lanes) ||
                        (bw_code > dp_panel->max_bw_code)) {
-               DRM_ERROR("read dpcd failed %d\n", rc);
-               return rc;
+               DRM_ERROR("Illegal link rate=%d lane=%d\n", 
dp_panel->link_info.rate,
+                               dp_panel->link_info.num_lanes);
+               return -EINVAL;
        }
 
        if (dp_panel->dfp_present) {
-- 
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