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 24733D730AD for ; Fri, 3 Apr 2026 19:05:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 84B0B10F37A; Fri, 3 Apr 2026 19:05:16 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=kwiboo.se header.i=@kwiboo.se header.b="rb+wIrcK"; dkim-atps=neutral Received: from smtp.forwardemail.net (smtp.forwardemail.net [149.28.215.223]) by gabe.freedesktop.org (Postfix) with ESMTPS id 31A2910F39D for ; Fri, 3 Apr 2026 19:05:15 +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=1775243114; bh=cb7kV5xrgzBNF02Z/hIuS/zVAc/l0KXvVzEjt546s3c=; b=rb+wIrcKQK1SkUaijqzNYYlQWf2+oVbbQi2pdwAdCaZGdlsGgaJkvCnrtjJYaShbpudi3dDRb ZKbnh1zSIS9BMhoYwtmxD06vEsvAnCEWk5yI60gCzGBMsltWFRuvpxBgUDezuOMBGL5FnrEVFWQ WWZrSxYTu/1MxpcoeETD+lWHjtUoa14a7zV8BJksBe0c2MrIzOg2EOUjPTpcz8L89VdhkxrGefh yh52v6NuKxA4W0QEsvJEJ+vAHmKAzXnr+duV+7aol+PhqoIY1dRgxtAOKslOxsA4gpGMpD+Bhvq qoMYyGahLo9ZO33gPbMLD0cndJ+vdZoMpcfwfEnq9DlA== X-Forward-Email-ID: 69d00ccedc98192b40b893e1 X-Forward-Email-Sender: rfc822; jonas@kwiboo.se, smtp.forwardemail.net, 149.28.215.223 X-Forward-Email-Version: 2.6.68 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 , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Christian Hewitt , Diederik de Haas , dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 09/13] drm: bridge: dw_hdmi: Use delayed_work to debounce hotplug event Date: Fri, 3 Apr 2026 18:52:55 +0000 Message-ID: <20260403185303.80748-10-jonas@kwiboo.se> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260403185303.80748-1-jonas@kwiboo.se> References: <20260403185303.80748-1-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" HDMI Specification Version 1.4b chapter 8.5 mentions: An HDMI Sink shall not assert high voltage level on its Hot Plug Detect pin when the E-EDID is not available for reading. A Source may use a high voltage level Hot Plug Detect signal to initiate the reading of E-EDID data. An HDMI Sink shall indicate any change to the contents of the E-EDID by driving a low voltage level pulse on the Hot Plug Detect pin. This pulse shall be at least 100 msec. Use a work queue to debounce reacting on HPD events to better handle a HPD low voltage level pulse when a sink changes the EDID. The 1100 msec hotplug debounce timeout was arbitrarily picked to match other drivers using same const, and testing using a Raspberry Pi Monitor seem to use a 200-300 msec pulse when going from standby to power on state. Signed-off-by: Jonas Karlman --- v3: New patch --- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 24 +++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index f3f8144ae98e..4d079b689b3b 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -51,6 +51,8 @@ #define HDMI14_MAX_TMDSCLK 340000000 +#define HOTPLUG_DEBOUNCE_MS 1100 + static const u16 csc_coeff_default[3][4] = { { 0x2000, 0x0000, 0x0000, 0x0000 }, { 0x0000, 0x2000, 0x0000, 0x0000 }, @@ -192,6 +194,7 @@ struct dw_hdmi { hdmi_codec_plugged_cb plugged_cb; struct device *codec_dev; enum drm_connector_status last_connector_result; + struct delayed_work hpd_work; }; const struct dw_hdmi_plat_data *dw_hdmi_to_plat_data(struct dw_hdmi *hdmi) @@ -2528,6 +2531,7 @@ static void dw_hdmi_connector_force(struct drm_connector *connector) mutex_lock(&hdmi->mutex); hdmi->force = connector->force; + hdmi->last_connector_result = connector->status; dw_hdmi_update_phy_mask(hdmi); mutex_unlock(&hdmi->mutex); } @@ -3046,6 +3050,16 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense) } EXPORT_SYMBOL_GPL(dw_hdmi_setup_rx_sense); +static void dw_hdmi_hpd_work(struct work_struct *work) +{ + struct dw_hdmi *hdmi = container_of(work, struct dw_hdmi, hpd_work.work); + + if (hdmi->bridge.dev) { + drm_helper_hpd_irq_event(hdmi->bridge.dev); + drm_bridge_hpd_notify(&hdmi->bridge, hdmi->last_connector_result); + } +} + static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) { struct dw_hdmi *hdmi = dev_id; @@ -3097,10 +3111,8 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) status == connector_status_connected ? "plugin" : "plugout"); - if (hdmi->bridge.dev) { - drm_helper_hpd_irq_event(hdmi->bridge.dev); - drm_bridge_hpd_notify(&hdmi->bridge, status); - } + mod_delayed_work(system_percpu_wq, &hdmi->hpd_work, + msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS)); } hdmi_writeb(hdmi, intr_stat, HDMI_IH_PHY_STAT0); @@ -3420,6 +3432,8 @@ struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev, goto err_res; } + INIT_DELAYED_WORK(&hdmi->hpd_work, dw_hdmi_hpd_work); + ret = devm_request_threaded_irq(dev, irq, dw_hdmi_hardirq, dw_hdmi_irq, IRQF_SHARED, dev_name(dev), hdmi); @@ -3552,6 +3566,8 @@ EXPORT_SYMBOL_GPL(dw_hdmi_probe); void dw_hdmi_remove(struct dw_hdmi *hdmi) { + disable_delayed_work_sync(&hdmi->hpd_work); + drm_bridge_remove(&hdmi->bridge); if (hdmi->audio && !IS_ERR(hdmi->audio)) -- 2.53.0