From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6047233149 for ; Fri, 26 Sep 2025 16:00:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758902450; cv=none; b=tTvns2ZVqMVNJRRJbpehn00NqVjDApBZeMQFFKYsceaZi7mymEuKjhLyOjsvbBR7P571KjJYfmW3/KyAytDlmCro9QbdU4wXsygqt15/4rCABxxdEQ/fAZ/BxwOOKyJk+JRkrWawm+YJed4zUW8urGZTJs9WMh+0OmJZ8lsM70Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758902450; c=relaxed/simple; bh=bSKlgcTE2tqnQAfvUw7h2KuSRdXrRYfsMe8uvhDe/2s=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=OkjPCauASiAFttC41L1g/IqC97wpFuXbMJpd4GBuL1K/cMFfq4IWWOHPuiP3ZlA6XkMz3xAux2WRDy7xM307JSzBlINz6CFNXRz+RdqMkV6tY6chJlppzcs+DadEStLVsbNCdxQiZWCDsK6qlWM6+S2mhyzQo9dPA0zmkNIs1w0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=pSEdxGvo; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="pSEdxGvo" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 35C8C4E40E0C; Fri, 26 Sep 2025 16:00:47 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 0C058606B5; Fri, 26 Sep 2025 16:00:47 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 927C4102F197A; Fri, 26 Sep 2025 18:00:44 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1758902446; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=Pyl7McX8p/BvXq+1eS++mIsDEQYJnykZVE13rAURX84=; b=pSEdxGvoMSA2wLwDyKPNC11bCZHACQd7041B62ZaVy8r3Cin3eZ6ivrLAgkw51kf5hTl/B /eVefzTFdgRc9Gw3dJns3lX5lEwyvV4IuNjrkIqLWUAbUJvcZpHKm4fpAQ6UyaaJxieb7q Ziy+KKKwAqPnm9o15Y/3FWc+litHwWYSYXl+cZRZEQkOPJIzYtnhCdEUIIkPiiP8ahq380 QuLFg/7RnbvTMFRC46BHyEdb7kkPjDBCpdJEeHmQLRzPTFFcArGE6PsAuG4+Wjh00usNCY kVbO5WBYl+d2Vn5fS75bXtrlpKJdLFtcPex4N2qgu40POPOYIzvnLxdADx4IGA== From: Luca Ceresoli Date: Fri, 26 Sep 2025 17:59:43 +0200 Subject: [PATCH 2/7] drm/encoder: drm_encoder_cleanup: take chain mutex while tearing down Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250926-drm-bridge-alloc-encoder-chain-mutex-v1-2-23b62c47356a@bootlin.com> References: <20250926-drm-bridge-alloc-encoder-chain-mutex-v1-0-23b62c47356a@bootlin.com> In-Reply-To: <20250926-drm-bridge-alloc-encoder-chain-mutex-v1-0-23b62c47356a@bootlin.com> To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec Cc: Hui Pu , Thomas Petazzoni , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Luca Ceresoli X-Mailer: b4 0.14.2 X-Last-TLS-Session-Version: TLSv1.3 drm_encoder_cleanup() modifies the encoder chain by removing bridges via drm_bridge_detach(). Protect this whole operation by taking the mutex, so any users iterating over the chain will not access it during the change. Signed-off-by: Luca Ceresoli --- drivers/gpu/drm/drm_encoder.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c index 3261f142baea30c516499d23dbf8d0acf5952cd6..3a04bedf9b759acd6826864b7f2cc9b861a8f170 100644 --- a/drivers/gpu/drm/drm_encoder.c +++ b/drivers/gpu/drm/drm_encoder.c @@ -195,9 +195,11 @@ void drm_encoder_cleanup(struct drm_encoder *encoder) * the indices on the drm_encoder after us in the encoder_list. */ + mutex_lock(&encoder->bridge_chain_mutex); list_for_each_entry_safe(bridge, next, &encoder->bridge_chain, chain_node) drm_bridge_detach(bridge); + mutex_unlock(&encoder->bridge_chain_mutex); drm_mode_object_unregister(dev, &encoder->base); kfree(encoder->name); -- 2.51.0