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: 12750706 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 3BE8FC433EF for ; Thu, 17 Feb 2022 22:42:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 69D3910E88B; Thu, 17 Feb 2022 22:42:07 +0000 (UTC) Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by gabe.freedesktop.org (Postfix) with ESMTPS id BB5E810E88B for ; Thu, 17 Feb 2022 22:42:06 +0000 (UTC) Received: by mail-pg1-x536.google.com with SMTP id 75so6242779pgb.4 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=TWZjpDIrrNqy5eR/dYAkz+dWnQYR9y3F/HgO45Q4IirPTinlx7LMXBlGV16hs03rQV FVy3VZlV1oYZd+2DN3HQnUpysNtpXRXEE+/+2NuVftKKYirHqwkHJqPXTZhGjYhvdIk9 hy9aPSWY5Sb1OELE8Uh2ih0nHW5bFvUlz47kKB7q0iyaFsWTWu32yBwggQ2NZDPMvclg IdcQIJvTe1eqkkcgykkdgXv6jStXytlIlZDT/R6jr3YLOSbKQzQnKByPhQYhuGOpYPZT XsWriyRH/lY9oOdSgFkSQT1xp92A/BuiDQM2VlXBPUF1ULTQXYAOZTskkMwQL+X8oZnl 4vOA== X-Gm-Message-State: AOAM533LFmCUDJ7tUaXYEhMS8ENKIUKasm3TjBrzu31DNH1I36XZSSlr 5kWjVkR+0FAuXTyhDmXH93iaag== 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 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-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: , Cc: Tomeu Vizoso , Jonas Karlman , Brian Norris , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Doug Anderson , linux-rockchip@lists.infradead.org, Jernej Skrabec , stable@vger.kernel.org, Sean Paul , Laurent Pinchart Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 *