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(unknown [61.154.14.86]) by smtp.qiye.163.com (Hmail) with ESMTP id 48b4fff21; Tue, 4 Aug 2026 16:17:34 +0800 (GMT+08:00) From: Damon Ding To: Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Heiko Stuebner , Andy Yan Cc: Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Dmitry Baryshkov , Marek Szyprowski , Sebastian Reichel , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Damon Ding Subject: [PATCH v2 09/10] drm/bridge: analogix_dp: Restrict forced connected status only for panel endpoint Date: Tue, 4 Aug 2026 16:17:16 +0800 Message-Id: <20260804081717.741404-10-damon.ding@rock-chips.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260804081717.741404-1-damon.ding@rock-chips.com> References: <20260804081717.741404-1-damon.ding@rock-chips.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-HM-Tid: 0a9fcbd9777003a8kunma7b8cbe762b0ed X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVlCQh4eVkJIQx5LSEIZSkkaQlYVFA kWGhdVEwETFhoSFyQUDg9ZV1kYEgtZQVlNSlVKTk9VSk9VQ01ZV1kWGg8SFR0UWUFZT0tIVUpLSE pKQk1VSktLVUpCWQY+ DKIM-Signature: a=rsa-sha256; b=RoKQnGWYAYRI7Qa3lvdPLalCuoRZUR+wcRtqd5S/f6K2s5PC8vLunb1kwJ2FtSXrOKj+EjsbMUpc4rPNa7/jF6u0e2FWxLzMut6IPJfCzd8Pe77wh/8rQUm0TUcIT8/l6fGkIfjWfxuH1pVFAv3CiSMUrqdCxJRBYxp0qEbz6CU=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=++hasEF6aBrRfCl+8wlVRjHt23leSsAweKpeIh4oR8k=; h=date:mime-version:subject:message-id:from; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260804_011740_134586_63E56DAE X-CRM114-Status: GOOD ( 14.04 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Limit the shortcut which unconditionally returns connected status when a next bridge exists. Only apply this logic if the last bridge in the chain is a panel. For all other cases, rely on analogix_dp_detect_hpd() to report accurate hotplug state. Background for the special handling: - If the chain ends with a DP connector bridge, the connector relies on analogix_dp to perform detection. We must avoid hardcoding connected status here. - For intermediate bridges such as PS8625 / PTN3460 without detect support [1], historically the bridge connector defaults to connected via drm_helper_probe_detect() when no per-bridge detect callback exists. Maintain compatibility by keeping the shortcut exclusively for panel endpoints. [1] https://lore.kernel.org/all/4939d55e-b560-4235-8295-adf8e48d9b74@samsung.com/ Reported-by: Heiko Stuebner Link: https://lore.kernel.org/all/5209243.oAaWjsssbx@diego/ Signed-off-by: Damon Ding --- .../gpu/drm/bridge/analogix/analogix_dp_core.c | 16 ++++++++++++++-- .../gpu/drm/bridge/analogix/analogix_dp_core.h | 1 + 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index f05db455b430..a5a50b9ab8a7 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -906,8 +906,15 @@ analogix_dp_bridge_detect(struct drm_bridge *bridge, struct drm_connector *conne struct analogix_dp_device *dp = to_dp(bridge); enum drm_connector_status status = connector_status_disconnected; - if (dp->plat_data->next_bridge) - return connector_status_connected; + /* + * Only assume connected when the bridge chain ends with a panel. + * Panel bridges lack a detect callback and historically rely on + * this shortcut. For other next bridge types (e.g., DP connector + * bridges), fall through to analogix_dp_detect_hpd() to report + * accurate hotplug state. + */ + if (dp->plat_data->next_bridge && dp->last_bridge_is_panel) + status = connector_status_connected; if (!analogix_dp_detect_hpd(dp)) status = connector_status_connected; @@ -920,6 +927,7 @@ static int analogix_dp_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags) { struct analogix_dp_device *dp = to_dp(bridge); + struct drm_bridge *last_bridge; int ret = 0; if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) { @@ -934,6 +942,10 @@ static int analogix_dp_bridge_attach(struct drm_bridge *bridge, dev_err(dp->dev, "failed to attach following panel or bridge (%d)\n", ret); return ret; } + + last_bridge = drm_bridge_chain_get_last_bridge(dp->encoder); + if (drm_bridge_is_panel(last_bridge)) + dp->last_bridge_is_panel = true; } return 0; diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h index 2066e575ce10..bcb5674801a2 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -168,6 +168,7 @@ struct analogix_dp_device { bool force_hpd; bool fast_train_enable; bool psr_supported; + bool last_bridge_is_panel; u8 dpcd[DP_RECEIVER_CAP_SIZE]; -- 2.34.1