From patchwork Fri Feb 25 13:45:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ricardo_Ca=C3=B1uelo?= X-Patchwork-Id: 12760364 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 BEAB8C433FE for ; Fri, 25 Feb 2022 13:55:16 +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=CYKHBFDGLnFCK/SH3NPErmo3HjeDGw913WN0vUx8PYU=; b=gWD86IZqYg0PvU YUoOulAwoWQ/uazYzd6O6/DIPxkA3mDzTLMSNJdEX6dz5A699vuzsD1cYgGKTYmskxkN9U+JaAymm F9k9Sk+7F7jP0P8Z4uPI0rcXEZTq9IwR0mHgeWwVNNrpLXO0rIHX67yYX6kTasw04rnxCdCU0bV+y 8Kd1Kw66ogcgF0ocv3WenMw6G9tEHUTUyEL/Z2geN5JEPjFxOBkwHaP3v/digdDLDLwSqtEdgRlUK 4fa4KCaKH9CeJZN3HuBLELezjiuVC5erR06YReKn8NGGHwNdpEIzSSt1nKULzApr3PUvwsTQaAwvk xZ9QohdstumkPYWv/nzA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nNb3t-005GSG-DK; Fri, 25 Feb 2022 13:55:09 +0000 Received: from bhuna.collabora.co.uk ([46.235.227.227]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nNaum-005DEb-MR for linux-mediatek@lists.infradead.org; Fri, 25 Feb 2022 13:45:51 +0000 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_Ca=C3=B1uelo?= To: dri-devel@lists.freedesktop.org Cc: =?utf-8?q?Ricardo_Ca=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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220225_054544_940351_9489F8A1 X-CRM114-Status: GOOD ( 11.43 ) 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 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 Cañuelo --- 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 *bridge) { struct drm_encoder *encoder; - if (!bridge) + if (!bridge || !bridge->dev) return; encoder = bridge->encoder; @@ -585,7 +585,7 @@ void drm_bridge_chain_pre_enable(struct drm_bridge *bridge) struct drm_encoder *encoder; struct drm_bridge *iter; - if (!bridge) + if (!bridge || !bridge->dev) return; encoder = bridge->encoder;