From patchwork Mon May 23 10:47:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guillaume Ranquet X-Patchwork-Id: 12858963 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 5344DC433FE for ; Mon, 23 May 2022 11:44:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6YbVzOVYBaIvhUISYWoNeMqhxlcUaR/V2dfas1zQV5A=; b=1WRlH13qoO3G0m QhL+BTKh8Emn7RaUjRYTpvu4z+XIIGaW1NErBMS5uC95DrCK2Xoruw/K2kxPYOQ9YfZHFhJanBeFE gGZzXPlsnScTIAq2fhbHgLPBdIA6TirriINYzI0b99g4YK0Jd5a2hXe+/TmWTbqLhLbZwPMX6Avjs YOezfWMOCh3jMfIcS+lA7YwuYy8fw/QebbQ9HTmq1igzigWdWBHXVHJXrPImdYTsCcSPgoE47M7ku jPLjEVfVT3nZ0a3CvyGC2s3JO1+HaNDseA39rMTtmdjywl522jawZVWV+m1O8IYPsH8LddMlqui8l Swfe0jQ/I1tuA92OGzEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nt6TZ-003oFY-96; Mon, 23 May 2022 11:43:53 +0000 Received: from mail-wm1-f66.google.com ([209.85.128.66]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nt5fd-003Qb5-QS for linux-mediatek@lists.infradead.org; Mon, 23 May 2022 10:52:20 +0000 Received: by mail-wm1-f66.google.com with SMTP id 184-20020a1c02c1000000b003974edd7c56so154686wmc.2 for ; Mon, 23 May 2022 03:52:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=hLfS42PaaSTIvwoBINmbgQcJWAC+mkxuv8Sro1ZZiBw=; b=h7Ar0XPc6m9I8Rf5wHDAfZoG1WMnfebvWZ5PMsjzR2Z5Qpy93Hzk2O1p0IJMPQPx2e fI+LdDbsC7B/XHPcDBpBpwFX4ePIq6AgQ23hN5ZUZq1rjV7+sLlE5NGePnl1iQPEVEEq mn2qZgeg/WZl5p5a2odv8KBJH3fwk7VlQ9q1iO81MSuZBBWfmB6c38cPcJShOKM7v+tY H/PXXEXLlGoPS4o2pzO3gvhyu7q07QXiiDcY9h425ZGqzmanPE1KiAZ54e6+VJNfJpIr sBLX1QZev0rIBy6QjmmBMVYMJPuoxirKfPtzyttNpRhvL+61lUwqvhwv6hmR8W0yckwZ z7dQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=hLfS42PaaSTIvwoBINmbgQcJWAC+mkxuv8Sro1ZZiBw=; b=DSEnW7F7qmex+bby8qC4MhuO75RLGyGZPpWru7xz4VGHVv3f+i9EyIIrL54IP15dMd 6Nls1rcQJDSXKib5A27HfJyDXOK6qGTgI8cSLLK2lNDrVsLz1vZFpuNmRH1UBwIbTcB9 vHBnwGQw7TW0bJQq1lVIaZ6H8jer1WB+pjggFgyU7LzMQ7/ztPIX/BJDLh5xdB9xRYAa Wn808tAwkKezM86id6tWlE01EKipeKwCti2klsJuNSEoltZQU0Rm4FgkSIqXBfdvOwSj bFadsk8Tcc78IhKnZXr3IKWo55rYbuJPc5ns9Q85lQzRPgD/V6QLeEDieci7tVZ6KuRM 8Ymg== X-Gm-Message-State: AOAM531PDr1MsRYHqcbXjOAJbm4iGj+O6MSfgjF4PduEXkcFToqTFVCF 53ZYBog7GLWiHyYVw6LAnRpnfw== X-Google-Smtp-Source: ABdhPJzde8+aBgbVlyoCCnCNTWr7Ur5rMTCZYCt2csAVS6LILQDcPXm+e3GmDaRs9bF2zxKHX6TnHA== X-Received: by 2002:a05:600c:42d3:b0:397:47ae:188c with SMTP id j19-20020a05600c42d300b0039747ae188cmr6383674wme.150.1653303136070; Mon, 23 May 2022 03:52:16 -0700 (PDT) Received: from localhost.localdomain (2a02-8440-6141-9d1b-3074-96af-9642-0003.rev.sfr.net. [2a02:8440:6141:9d1b:3074:96af:9642:3]) by smtp.gmail.com with ESMTPSA id n11-20020a7bc5cb000000b003942a244f38sm8453607wmk.17.2022.05.23.03.52.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 May 2022 03:52:15 -0700 (PDT) From: Guillaume Ranquet To: Chun-Kuang Hu , Philipp Zabel , David Airlie , Daniel Vetter , Rob Herring , Krzysztof Kozlowski , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Matthias Brugger , Chunfeng Yun , Kishon Vijay Abraham I , Vinod Koul , Helge Deller , CK Hu , Jitao shi Cc: Rex-BC Chen , dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-phy@lists.infradead.org, linux-fbdev@vger.kernel.org Subject: [PATCH v10 20/21] drm/mediatek: add hpd debounce Date: Mon, 23 May 2022 12:47:53 +0200 Message-Id: <20220523104758.29531-21-granquet@baylibre.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220523104758.29531-1-granquet@baylibre.com> References: <20220523104758.29531-1-granquet@baylibre.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220523_035217_935990_1A8EB916 X-CRM114-Status: GOOD ( 20.48 ) X-BeenThere: linux-mediatek@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-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org From: Jitao Shi From the DP spec 1.4a chapter 3.3, upstream devices should implement HPD signal de-bouncing on an external connection. A period of 100ms should be used to detect an HPD connect event. To cover these cases, HPD de-bounce should be implemented only after HPD low has been detected for at least 100ms. Therefore, 1. If HPD is low (which means plugging out) for longer than 100ms: we need to do de-bouncing (which means we need to wait for 100ms). 2. If HPD low is for less than 100ms: we don't need to care about the de-bouncing. In this patch, we start a 100ms timer and use a need_debounce boolean to implement the feature. Two cases when HPD is high: 1. If the timer is expired (>100ms): - need_debounce is true. - When HPD high (plugging event comes), need_debounce will be true and then we need to do de-bouncing (wait for 100ms). 2. If the timer is not expired (<100ms): - need_debounce is false. - When HPD high (plugging event comes), need_debounce will be false and no need to do de-bouncing. HPD_______ __________________ | |<- 100ms -> |____________| <- 100ms -> Without HPD de-bouncing, USB-C to HDMI Adapaters will not be detected. The change has been successfully tested with the following devices: - Dell Adapter - USB-C to HDMI - Acer 1in1 HDMI dongle - Ugreen 1in1 HDMI dongle - innowatt HDMI + USB3 hub - Acer 2in1 HDMI dongle - Apple 3in1 HDMI dongle (A2119) - J5Create 3in1 HDMI dongle (JAC379) Tested-by: Rex-BC Chen Reviewed-by: Rex-BC Chen Signed-off-by: Jitao Shi Signed-off-by: Guillaume Ranquet --- drivers/gpu/drm/mediatek/mtk_dp.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index 4789853ec5ff..c056bc3ca9f6 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -154,6 +154,8 @@ struct mtk_dp { struct mutex dp_lock; struct drm_connector *conn; + bool need_debounce; + struct timer_list debounce_timer; }; static struct regmap_config mtk_dp_regmap_config = { @@ -1970,6 +1972,9 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev) if (event < 0) return IRQ_HANDLED; + if (mtk_dp->need_debounce && mtk_dp->train_info.cable_plugged_in) + msleep(100); + if (mtk_dp->drm_dev) { dev_info(mtk_dp->dev, "drm_helper_hpd_irq_event\n"); drm_helper_hpd_irq_event(mtk_dp->bridge.dev); @@ -2047,6 +2052,11 @@ static irqreturn_t mtk_dp_hpd_isr_handler(struct mtk_dp *mtk_dp) } train_info->cable_state_change = true; + if (!train_info->cable_plugged_in) { + mod_timer(&mtk_dp->debounce_timer, jiffies + msecs_to_jiffies(100) - 1); + mtk_dp->need_debounce = false; + } + return IRQ_WAKE_THREAD; } @@ -2474,6 +2484,13 @@ static const struct drm_bridge_funcs mtk_dp_bridge_funcs = { .detect = mtk_dp_bdg_detect, }; +static void mtk_dp_debounce_timer(struct timer_list *t) +{ + struct mtk_dp *mtk_dp = from_timer(mtk_dp, t, debounce_timer); + + mtk_dp->need_debounce = true; +} + static int mtk_dp_probe(struct platform_device *pdev) { struct mtk_dp *mtk_dp; @@ -2547,6 +2564,9 @@ static int mtk_dp_probe(struct platform_device *pdev) else mtk_dp->bridge.type = DRM_MODE_CONNECTOR_DisplayPort; + mtk_dp->need_debounce = true; + timer_setup(&mtk_dp->debounce_timer, mtk_dp_debounce_timer, 0); + pm_runtime_enable(dev); pm_runtime_get_sync(dev); @@ -2559,6 +2579,7 @@ static int mtk_dp_remove(struct platform_device *pdev) platform_device_unregister(mtk_dp->phy_dev); mtk_dp_video_mute(mtk_dp, true); + del_timer_sync(&mtk_dp->debounce_timer); pm_runtime_disable(&pdev->dev);