From patchwork Wed Mar 2 02:11:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Norris X-Patchwork-Id: 12765385 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 93E22C433F5 for ; Wed, 2 Mar 2022 02:11:58 +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=G85SYzNT1G3pKo+8wgiHPWr8dH8TBdLjhylgDSQs/HE=; b=0c6wxb7I79/x3g FbM0bhI1dt2H5kiIwdI+SE9ia1J5YwlmCoZ61ZlBQOjayhZaiUYig1zoNX+bSlQTQijtjGO+9Ck2d 8mj+3hyoPmgBqqinho60K+JEunTxQC2CsZAW0nZgX9AuFBYT01Y3HriZjuIRDAXq+mQrxhUtzlUDR 00CwJRJZMEHXpilxbB9j1prZ4TL9cwKSgb87pYzqa4gXYwI66MNvyri6XWWf4/1geQIED84i1pv5X x+854kOGGbVq89x1ilvwPAAiCpTT3O11iIF2LsaYhSv5I8WRfh2X7yFIUTejmErWdTkQ6Z4/bSYba QN0UYncicu906OslAXJw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPET4-0013M9-7X; Wed, 02 Mar 2022 02:11:54 +0000 Received: from mail-pj1-x1031.google.com ([2607:f8b0:4864:20::1031]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPET1-0013LB-0K for linux-rockchip@lists.infradead.org; Wed, 02 Mar 2022 02:11:52 +0000 Received: by mail-pj1-x1031.google.com with SMTP id bx5so491219pjb.3 for ; Tue, 01 Mar 2022 18:11:50 -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=F209WZI5vXfOkAuKwi/GeBW/6ePfEyIdvCWtsBXsuzo=; b=iu79tfZfv3syKE43Jc12ubc5bbfcm39Ba+iZqiH3YF6xx2VPj3Kue+5S3kBvepBO5q kdqhPnMePsk0a9w8OIsw9SA9VZIf2pxacttjWVOEkepKtTZDlhYIL9v+fhG0XVWGlEwh Se8dU2iquV0Zmid8y13HZf9VaAMALn+8EStJ8= 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=F209WZI5vXfOkAuKwi/GeBW/6ePfEyIdvCWtsBXsuzo=; b=E6RpzppP8mi65d9p4iem6CDYpdqI2lbjcrbDYI8KL8/UAJxbIssQfjPKZt6nnQhSBI QTJiJ2vLfQr13dgRn6GX2ocW1xGwk3u1ivOAnLyBLHQhLK/vuTA6lLpBAMvpuC0r+PbR zFlUGE0oF1/qlYryqgSNyes5W7MZLkjoAV5xLqG6G/0NQC8NZUtr+cHU4DUDDp29ptV2 TUBjjJ/uOVhEhUaZr24PphDO/LEkhGpm0dyrpxmHFRlvE/iOiL78EZJ7SDBwRQLiiz5J yHgmjMNWmCfdUmyOqCzho8g0pmSnqtd++/xfMOtfuRbUJtGSRMm9bcxQsoYvO630BMMZ qcYw== X-Gm-Message-State: AOAM531ImCwapkrUXsxbY5up0yo5i4tEmL6OgUxgNvsFXFRqnNVUwejx aT9UNrm0vE+MtdXsouaJ/1mFxg== X-Google-Smtp-Source: ABdhPJwkV2kz8kBnK1WvzDVCNJRbzW5x17kwBoiaU5GguV6QDiHBp0jHTeZkBJ3WlYzD/yEyKxFkhQ== X-Received: by 2002:a17:90a:4609:b0:1bc:f41e:5390 with SMTP id w9-20020a17090a460900b001bcf41e5390mr23827824pjg.27.1646187110276; Tue, 01 Mar 2022 18:11:50 -0800 (PST) Received: from localhost ([2620:15c:202:201:ddf3:7c12:38c:3c61]) by smtp.gmail.com with UTF8SMTPSA id f15-20020a056a0022cf00b004f3b99a6c43sm18651207pfj.219.2022.03.01.18.11.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 01 Mar 2022 18:11:49 -0800 (PST) From: Brian Norris To: Andrzej Hajda , Neil Armstrong Cc: Jonas Karlman , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Sean Paul , Jernej Skrabec , Doug Anderson , linux-rockchip@lists.infradead.org, Laurent Pinchart , Brian Norris , stable@vger.kernel.org, Tomeu Vizoso Subject: [PATCH v4 1/2] drm/bridge: analogix_dp: Grab runtime PM reference for DP-AUX Date: Tue, 1 Mar 2022 18:11:38 -0800 Message-Id: <20220301181107.v4.1.I773a08785666ebb236917b0c8e6c05e3de471e75@changeid> X-Mailer: git-send-email 2.35.1.574.g5d30c73bfb-goog MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220301_181151_083610_AC2724CA X-CRM114-Status: GOOD ( 13.87 ) 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 v4: - Add Doug's Reviewed-by 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 *