From patchwork Thu Feb 17 22:41:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Norris X-Patchwork-Id: 12750694 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 F05E4C433F5 for ; Thu, 17 Feb 2022 22:42:17 +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: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:In-Reply-To:References: List-Owner; bh=N/D98IOsE/7406fFah7jMc64uME3VBSClY3077L5I4U=; b=rWhO96nnZTyBLo 3/JEbkbua6B+Qq3xOApCYfojqGZhsQiRfeU3u3FhCKo40K/rnO7TDLXx4xwSs+pM3k2/2s9ASJL2S J0qYHg2+7icYYoICe+fnbnFmpoaTWuXlgtus8ljzKsH+mU0WpiwIMMAk+vP7kXyX50zApUgx4gdwK 6zAaYkExa3sTIV3WuibN70RtzSy/orT4z2XogucF4DgH9ds8IpdmksUDmFTS/QlNGvkTqTMxdj4AW UwncbSDnvI6J4RqNlXjpMC5rLY+r2xv8LXUzL1B0tvzc2w9jFVZR4N4r/CDihBkq+kGe4dRCWkKF+ XSGiSpOJjoGYlJmvT4tw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nKpTW-00CNhn-HW; Thu, 17 Feb 2022 22:42:10 +0000 Received: from mail-pg1-x529.google.com ([2607:f8b0:4864:20::529]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nKpTU-00CNgh-O0 for linux-rockchip@lists.infradead.org; Thu, 17 Feb 2022 22:42:10 +0000 Received: by mail-pg1-x529.google.com with SMTP id 132so6239836pga.5 for ; Thu, 17 Feb 2022 14:42:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=/pFhxh4a1mIJWKVvwWf0TWI0PzyzDNvxgd8MaYxtB4g=; b=DRjZUlF38aKhKGF1HEEXpShz5dNW4rV1EZ3PJsdeXyBLxzGJJMj2+9g6pi+MiKGhYt H+9E29WZ8V4Np9zsahnlGJmkvOu6FMFXZxC9SU+qF5bJdkcsbldinSAPqonRI6Ftb1Dz YKCtyN3JvqpZZ/nc5796hnay3gO0nfEdVSefs= 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:mime-version :content-transfer-encoding; bh=/pFhxh4a1mIJWKVvwWf0TWI0PzyzDNvxgd8MaYxtB4g=; b=NSt4OX8DAZf2jRRifjjUdTogTDYI08nYNgMaKCZ69r5fVq70N0JzakCB4tRsgcDae2 BTGpkrQEzZBKk0WoG0SFcoTefZvT6d+0LQvynd/jP3I+5nbnR0DZa8N6rIYBicw7dLTh GXM17DT0Z1lS4DxqFgveX6a6aZmjrq+1gZJb2W4ooj5N72I7XsEW0dCY/WygY1vyl4T4 KF95HIoiJxgrI9T/MVof3eX6ZsUbLqGJ298DS6gpdfmPKYCsdSzqggkMqhg0ANk9baRr V3T+7TrDnnovPpaJPtDWs6AiZT6WnfFaCObd45m+cTNLeiLm8q+63kjSZflSR4xV/7qe y90A== X-Gm-Message-State: AOAM5325zCEEwx+0ao70Tmr588rb0QkKIAPXogCrCAr5Afrph4n012Vz O33rFK5HfH7zM6SD40fBrAR5bQ== X-Google-Smtp-Source: ABdhPJx0I/9dms8bGvA0MQ9aczlCf/u6f2qI/Tw9lU7d6SMBvt5gmujVGb3LwnbbS//bPCI4KYGOjg== X-Received: by 2002:aa7:83c2:0:b0:4e0:91c1:6795 with SMTP id j2-20020aa783c2000000b004e091c16795mr4885484pfn.54.1645137726160; Thu, 17 Feb 2022 14:42:06 -0800 (PST) Received: from localhost ([2620:15c:202:201:677e:1914:4c14:1662]) by smtp.gmail.com with UTF8SMTPSA id u1sm628435pfg.151.2022.02.17.14.42.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 17 Feb 2022 14:42:05 -0800 (PST) From: Brian Norris To: Andrzej Hajda , Neil Armstrong Cc: linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, Doug Anderson , Sean Paul , Jernej Skrabec , dri-devel@lists.freedesktop.org, Laurent Pinchart , Jonas Karlman , Brian Norris , stable@vger.kernel.org, Tomeu Vizoso Subject: [PATCH v3 1/2] drm/bridge: analogix_dp: Grab runtime PM reference for DP-AUX Date: Thu, 17 Feb 2022 14:41:45 -0800 Message-Id: <20220217144136.v3.1.I773a08785666ebb236917b0c8e6c05e3de471e75@changeid> X-Mailer: git-send-email 2.35.1.265.g69c8d7142f-goog MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220217_144208_788490_2E856039 X-CRM114-Status: GOOD ( 13.58 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org If the display is not enable()d, then we aren't holding a runtime PM reference here. Thus, it's easy to accidentally cause a hang, if user space is poking around at /dev/drm_dp_aux0 at the "wrong" time. Let's get a runtime PM reference, and check that we "see" the panel. Don't force any panel power-up, etc., because that can be intrusive, and that's not what other drivers do (see drivers/gpu/drm/bridge/ti-sn65dsi86.c and drivers/gpu/drm/bridge/parade-ps8640.c.) Fixes: 0d97ad03f422 ("drm/bridge: analogix_dp: Remove duplicated code") Cc: Cc: Tomeu Vizoso Signed-off-by: Brian Norris Reviewed-by: Douglas Anderson --- Changes in v3: - Avoid panel power-up; just check for HPD state, and let the rest happen "as-is" (e.g., time out, if the caller hasn't prepared things properly) Changes in v2: - Fix spelling in Subject - DRM_DEV_ERROR() -> drm_err() - Propagate errors from un-analogix_dp_prepare_panel() drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index b7d2e4449cfa..16be279aed2c 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1632,8 +1632,19 @@ static ssize_t analogix_dpaux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { struct analogix_dp_device *dp = to_dp(aux); + int ret; + + pm_runtime_get_sync(dp->dev); + + ret = analogix_dp_detect_hpd(dp); + if (ret) + goto out; - return analogix_dp_transfer(dp, msg); + ret = analogix_dp_transfer(dp, msg); +out: + pm_runtime_put(dp->dev); + + return ret; } struct analogix_dp_device *