From nobody Sun Sep 22 09:35:02 2024 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3FFBC433FE for ; Fri, 25 Feb 2022 13:45:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241645AbiBYNqT (ORCPT ); Fri, 25 Feb 2022 08:46:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241631AbiBYNqO (ORCPT ); Fri, 25 Feb 2022 08:46:14 -0500 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0402B210D75 for ; Fri, 25 Feb 2022 05:45:43 -0800 (PST) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: rcn) with ESMTPSA id 38B651F45F94 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1645796741; bh=6IuTiAPuhKDYgNwCLKRyc4SunUJTB6ruZFYFsOvvpvs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=furnXzpdMdgCyVoYEJ4jDsNkBjXVwWUIBhNi74Q0yGH4QrCYy2xcC23hpHNo4n5G1 y8Ob0c1jgVIFTYAcUYS0VgI+V4cihoITEyo8tyqT6WCgnBVRZAwEIIomHmYKBxSzBt Dht/iRxyKUmfqcBqP4xEmfexO2cMyX4S0ivgJEH+iaqsHPSzatnnyPqq1iRfrV4b4u qfp/5GFOhhwNbEnaYRe9iWYSMgpbdoygnLQc8OU1T8IM4sTQQYPQz75DX31oGd8161 ibLHJGZwlRfOAm0FWAFpDkxesQSeTlLajZta2f58kEj2pvFTU9sy/6WHJQ3UtXQ8ic 0d/WRZ7lQBuGw== From: =?UTF-8?q?Ricardo=20Ca=C3=B1uelo?= To: dri-devel@lists.freedesktop.org Cc: =?UTF-8?q?Ricardo=20Ca=C3=B1uelo?= , linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, kernel@collabora.com, andrzej.hajda@intel.com, narmstrong@baylibre.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org Subject: [PATCH 2/2] drm/bridge: Add extra checks in pre_enable and post_enable Date: Fri, 25 Feb 2022 14:45:04 +0100 Message-Id: <20220225134504.457245-3-ricardo.canuelo@collabora.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220225134504.457245-1-ricardo.canuelo@collabora.com> References: <20220225134504.457245-1-ricardo.canuelo@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Depending on the bridge code, certain userspace events during a driver teardown (such as a DRM ioctl call) might cause a race condition where the drm_bridge_chain_pre_enable() and drm_bridge_chain_post_enable() functions could be called for a bridge that has just been detached and removed from the bridge chain of an encoder. This change makes these functions a bit more robust by bailing out if the bridge has already been detached. Tested on an Acer Chromebook R13 (Elm, MT8173) with Debian Sid. Signed-off-by: Ricardo Ca=C3=B1uelo --- drivers/gpu/drm/drm_bridge.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index c96847fc0ebc..e074aa456dd1 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -529,7 +529,7 @@ void drm_bridge_chain_post_disable(struct drm_bridge *b= ridge) { struct drm_encoder *encoder; =20 - if (!bridge) + if (!bridge || !bridge->dev) return; =20 encoder =3D bridge->encoder; @@ -585,7 +585,7 @@ void drm_bridge_chain_pre_enable(struct drm_bridge *bri= dge) struct drm_encoder *encoder; struct drm_bridge *iter; =20 - if (!bridge) + if (!bridge || !bridge->dev) return; =20 encoder =3D bridge->encoder; --=20 2.25.1