When the display pipeline includes a display-connector bridge with hpd-gpios configured, the connector's hotplug status is managed by the display-connector bridge through its GPIO, not by the Analogix DP controller's native HPD. In this configuration, the DP controller's internal HPD polling in analogix_dp_detect_hpd() does not reflect the actual connection state.
At attach time, detect whether a downstream bridge provides HPD events (DRM_BRIDGE_OP_HPD) while none of them provides detection (DRM_BRIDGE_OP_DETECT). When found, switch to hpd notify mode: cache the connection status reported through the .hpd_notify callback, mute the controller's native HPD interrupts and skip their initialization, and trust the cached status instead of polling the typically unconnected native HPD pin. Suggested-by: Heiko Stuebner <[email protected]> Link: https://lore.kernel.org/all/5609825.iZASKD2KPV@diego/ Signed-off-by: Damon Ding <[email protected]> --- Changes in v3: - Introduce hpd_notify_mode flag to skip native HPD operations when HPD comes from a downstream bridge. --- .../drm/bridge/analogix/analogix_dp_core.c | 27 ++++++++++++++++++- .../drm/bridge/analogix/analogix_dp_core.h | 2 ++ .../gpu/drm/bridge/analogix/analogix_dp_reg.c | 7 +++-- 3 files changed, 33 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index df898f314254..90245d55d1d2 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -45,7 +45,7 @@ static const bool verify_fast_training; static bool analogix_dp_require_pm_for_hpd_irq(struct analogix_dp_device *dp) { return analogix_dp_is_rockchip(dp->plat_data->dev_type) && !dp->hpd_gpiod && - !dp->force_hpd; + !dp->force_hpd && !dp->hpd_notify_mode; } static void analogix_dp_init_dp(struct analogix_dp_device *dp) @@ -936,6 +936,21 @@ static bool analogix_dp_bridge_force_connected(struct analogix_dp_device *dp) return force_connected; } +static bool analogix_dp_has_downstream_hpd(struct analogix_dp_device *dp) +{ + bool hpd_bridge = false; + + drm_for_each_bridge_in_chain_from(dp->bridge.next_bridge, bridge) { + if (bridge->ops & DRM_BRIDGE_OP_DETECT) + return false; + + if (bridge->ops & DRM_BRIDGE_OP_HPD) + hpd_bridge = true; + } + + return hpd_bridge; +} + static int analogix_dp_bridge_attach(struct drm_bridge *bridge, struct drm_encoder *encoder, enum drm_bridge_attach_flags flags) @@ -964,6 +979,7 @@ static int analogix_dp_bridge_attach(struct drm_bridge *bridge, * accurate hotplug state. */ dp->force_connected_mode = analogix_dp_bridge_force_connected(dp); + dp->hpd_notify_mode = analogix_dp_has_downstream_hpd(dp); } return 0; @@ -1260,6 +1276,14 @@ static void analogix_dp_bridge_atomic_post_disable(struct drm_bridge *bridge, DRM_ERROR("Failed to enable psr (%d)\n", ret); } +static void analogix_dp_bridge_notify(struct drm_bridge *bridge, struct drm_connector *connector, + enum drm_connector_status status) +{ + struct analogix_dp_device *dp = to_dp(bridge); + + dp->connection_notified = (status == connector_status_connected); +} + static const struct drm_bridge_funcs analogix_dp_bridge_funcs = { .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, @@ -1272,6 +1296,7 @@ static const struct drm_bridge_funcs analogix_dp_bridge_funcs = { .attach = analogix_dp_bridge_attach, .edid_read = analogix_dp_bridge_edid_read, .detect = analogix_dp_bridge_detect, + .hpd_notify = analogix_dp_bridge_notify, }; static int analogix_dp_dt_parse_lanes_map(struct analogix_dp_device *dp) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h index 5f5698c73d88..9f25fb6545ad 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -171,6 +171,8 @@ struct analogix_dp_device { bool fast_train_enable; bool psr_supported; bool force_connected_mode; + bool hpd_notify_mode; + bool connection_notified; u8 dpcd[DP_RECEIVER_CAP_SIZE]; diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c index abbcdba1a438..4c5e18d40dad 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c @@ -193,7 +193,7 @@ void analogix_dp_config_interrupt(struct analogix_dp_device *dp) writel(0, dp->reg_base + ANALOGIX_DP_COMMON_INT_MASK_2); writel(0, dp->reg_base + ANALOGIX_DP_COMMON_INT_MASK_3); - if (dp->hpd_gpiod) { + if (dp->hpd_gpiod || dp->hpd_notify_mode) { analogix_dp_mute_hpd_interrupt(dp, HPD_IRQ_ALL); return; } @@ -435,7 +435,7 @@ void analogix_dp_init_hpd(struct analogix_dp_device *dp) { u32 reg; - if (dp->hpd_gpiod) + if (dp->hpd_gpiod || dp->hpd_notify_mode) return; analogix_dp_clear_hotplug_interrupts(dp, HPD_IRQ_ALL); @@ -539,6 +539,9 @@ int analogix_dp_get_plug_in_status(struct analogix_dp_device *dp) if (dp->hpd_gpiod) { if (gpiod_get_value(dp->hpd_gpiod)) return 0; + } else if (dp->hpd_notify_mode) { + if (dp->connection_notified) + return 0; } else { reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3); if (reg & HPD_STATUS) -- 2.34.1
