From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A192ECD4851 for ; Sat, 16 May 2026 18:51:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D47D210E57E; Sat, 16 May 2026 18:51:04 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=kwiboo.se header.i=@kwiboo.se header.b="K2mtfUJs"; dkim-atps=neutral Received: from smtp.forwardemail.net (smtp.forwardemail.net [121.127.44.66]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2CCB310E57E for ; Sat, 16 May 2026 18:51:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kwiboo.se; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-ID: Date: Subject: Cc: To: From; q=dns/txt; s=fe-e1b5cab7be; t=1778957462; bh=LByMhDRnSw/19GAWOU8RQ0GafZjOhHwQpSIXnN3970I=; b=K2mtfUJsiFShgEqdQ3hc+BRRY4di/cKKzZk6SUn17Hijj5rAg+zrKbjFKopl8IPIDI+L12E0i +/za25h1vkcdV/Vt1dn0t4WExrjchMdhyJhGZg9ToRKH98OlsfDhqrJh6Vzuxl8nbLvfxdRNuBa 7aHNo418gDgiwauqG/3Q/nafB3DjlsK72m5J9is3/CJyDEn0b0lfFfV0R/DOtYHafI8Jluzsqm+ /m6dpY14bSPGUblcDLaGJKbbKPx60WKR6FlKwUDDY4Ag+zLeJlaHO0Fala62/qNLCkwEIBUJYgL a+kt6wyuH4ZHqkzFg5Ikc06m8YAdPBhz0aOIQBxJ4WqA== X-Forward-Email-ID: 6a08b9fd79c7625f20eeeedc X-Forward-Email-Sender: rfc822; jonas@kwiboo.se, smtp.forwardemail.net, 121.127.44.66 X-Forward-Email-Version: 2.8.12 X-Forward-Email-Website: https://forwardemail.net X-Complaints-To: abuse@forwardemail.net X-Report-Abuse: abuse@forwardemail.net X-Report-Abuse-To: abuse@forwardemail.net From: Jonas Karlman To: Andrzej Hajda , Neil Armstrong , Robert Foss , Heiko Stuebner , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Liu Ying , Sandy Huang , Andy Yan , Chen-Yu Tsai , Christian Hewitt , Diederik de Haas , Nicolas Frattaroli , Dmitry Baryshkov , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-sunxi@lists.linux.dev, imx@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v6 17/22] drm: bridge: dw_hdmi: Drop call to drm_bridge_hpd_notify() Date: Sat, 16 May 2026 18:38:27 +0000 Message-ID: <20260516183838.2024991-18-jonas@kwiboo.se> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260516183838.2024991-1-jonas@kwiboo.se> References: <20260516183838.2024991-1-jonas@kwiboo.se> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The use of calls to both drm_helper_hpd_irq_event() and drm_bridge_hpd_notify() from the HPD IRQ handler may cause multiple hotplug uevents and modesets when the bridge connector is used. Use of drm_helper_hpd_irq_event() cause the internal DRM function check_connector_changed() to be called, which in turn calls the connector detect()/force() funcs to detect any connection status or epoch changes, and when changed trigger a hotplug uevent. This also help ensure that EDID and CEC phys addr is updated. If only a call drm_bridge_hpd_notify() would be used, a custom connector status/EDID change detection logic needs to be implemented, to fully match what check_connector_changed() already provides. The bridge connector detect() func also ensures that any hpd_notify() funcs are called for all bridges in the chain, so there is not really any need to have a call to drm_bridge_hpd_notify() here. With both calls there is two hotplug uevents, two modesets and a total of four .hpd_notify() calls (using a bridge connector): dw_hdmi_irq(): EVENT=plugout drm_helper_hpd_irq_event(): dw_hdmi_bridge_hpd_notify(status=2) [drm:check_connector_changed] [CONNECTOR:46:HDMI-A-1] status updated from connected to disconnected [drm:check_connector_changed] [CONNECTOR:46:HDMI-A-1] Changed epoch counter 1 => 2 [drm:drm_sysfs_connector_hotplug_event] [CONNECTOR:46:HDMI-A-1] generating connector hotplug event drm_client_hotplug(): [drm:drm_fb_helper_hotplug_event] [drm:drm_client_modeset_probe] [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:46:HDMI-A-1] dw_hdmi_bridge_hpd_notify(status=2) [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:46:HDMI-A-1] disconnected [drm:drm_edid_connector_update] [CONNECTOR:46:HDMI-A-1] EDID changed, epoch counter 3 [drm:drm_client_modeset_probe] No connectors reported connected with modes [drm:drm_client_modeset_probe] [CONNECTOR:46:HDMI-A-1] enabled? no [drm:drm_client_firmware_config.isra.0] Not using firmware configuration [drm:drm_client_modeset_probe] picking CRTCs for 3840x2160 config [drm:drm_client_hotplug] fbdev: ret=0 drm_bridge_hpd_notify(): dw_hdmi_bridge_hpd_notify(status=2) [drm:drm_sysfs_connector_hotplug_event] [CONNECTOR:46:HDMI-A-1] generating connector hotplug event drm_client_hotplug(): [drm:drm_fb_helper_hotplug_event] [drm:drm_client_modeset_probe] [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:46:HDMI-A-1] dw_hdmi_bridge_hpd_notify(status=2) [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:46:HDMI-A-1] disconnected [drm:drm_client_modeset_probe] No connectors reported connected with modes [drm:drm_client_modeset_probe] [CONNECTOR:46:HDMI-A-1] enabled? no [drm:drm_client_firmware_config.isra.0] Not using firmware configuration [drm:drm_client_modeset_probe] picking CRTCs for 3840x2160 config [drm:drm_client_hotplug] fbdev: ret=0 Change to only call drm_helper_hpd_irq_event() from HPD IRQ handler to ensure that only one hotplug uevent is sent to userspace when connection status or EDID changes. With only a call the drm_helper_hpd_irq_event() there is only a single hotplug uevent and only two .hpd_notify() calls: dw_hdmi_irq(): EVENT=plugout drm_helper_hpd_irq_event(): dw_hdmi_bridge_hpd_notify(status=2) [drm:check_connector_changed] [CONNECTOR:46:HDMI-A-1] status updated from connected to disconnected [drm:check_connector_changed] [CONNECTOR:46:HDMI-A-1] Changed epoch counter 1 => 2 [drm:drm_sysfs_connector_hotplug_event] [CONNECTOR:46:HDMI-A-1] generating connector hotplug event drm_client_hotplug(): [drm:drm_fb_helper_hotplug_event] [drm:drm_client_modeset_probe] [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:46:HDMI-A-1] dw_hdmi_bridge_hpd_notify(status=2) [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:46:HDMI-A-1] disconnected [drm:drm_edid_connector_update] [CONNECTOR:46:HDMI-A-1] EDID changed, epoch counter 3 [drm:drm_client_modeset_probe] No connectors reported connected with modes [drm:drm_client_modeset_probe] [CONNECTOR:46:HDMI-A-1] enabled? no [drm:drm_client_firmware_config.isra.0] Not using firmware configuration [drm:drm_client_modeset_probe] picking CRTCs for 3840x2160 config [drm:drm_client_hotplug] fbdev: ret=0 Tested-by: Diederik de Haas # Rock64, RockPro64, Quartz64-B Signed-off-by: Jonas Karlman --- v6: Drop the call from IRQ handler instead, prior to use of a HPD delayed work to avoid a possible deadlock with use of sync() calls in the bridge hpd_disable() ops, Update commit message, Collect t-b tag v5: New patch --- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index e9c4e24c090c..6cc7b2a860bd 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -3101,10 +3101,8 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) status == connector_status_connected ? "plugin" : "plugout"); - if (hdmi->bridge.dev) { + if (hdmi->bridge.dev) drm_helper_hpd_irq_event(hdmi->bridge.dev); - drm_bridge_hpd_notify(&hdmi->bridge, status); - } } hdmi_writeb(hdmi, intr_stat, HDMI_IH_PHY_STAT0); -- 2.54.0