From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B36321C84B2 for ; Wed, 17 Sep 2025 08:31:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758097903; cv=none; b=I730SGc8/DZMTpYwUdQa0fe6udQwpS3yYxRfH3eQyYUn7z7qUVYtTCrJhTEUpV7K//eP9SzDkQY6x+zd3PzXNJjUnvdWJmD57t3+HxX3ITzqHNnHUVqGhtNwOfKAr7+uUrgolNrMSqNg0IQbtYOK4ZCUDbvHFApRuQNnIfExsvw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758097903; c=relaxed/simple; bh=M9UmLXFmf/H+p0ZBYHoX3xo/PpwRpsIwOwZtUvIBDGc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GlLcMLS1euu3jLfkVmGqXKdBN/yHvmdsPIFPRdK0CMR6Hv2wQODjlTMSsyIHusdPhtTp7guGUveKBNXHC4Om15F7m47YhjfkJnq2XJ3xdr2jQlETyrZyId3ZJR8IMeDujj0l6Pj/6igo5a5j8NFFlOJgPc1OktrY2XSREAr98eQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D32F012FC; Wed, 17 Sep 2025 01:31:26 -0700 (PDT) Received: from [10.1.31.40] (unknown [10.1.31.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 936693F673; Wed, 17 Sep 2025 01:31:33 -0700 (PDT) Message-ID: Date: Wed, 17 Sep 2025 09:31:32 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3] coresight: Fix possible deadlock in coresight_panic_cb Content-Language: en-GB To: Leo Yan , Sean Anderson Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, Yeoreum Yun , Mike Leach , Linu Cherian , linux-kernel@vger.kernel.org, Alexander Shishkin , James Clark References: <20250912151314.3761026-1-sean.anderson@linux.dev> <20250915095820.GH12516@e132581.arm.com> <3e618117-96bd-44f3-bede-7cadfe0264dd@linux.dev> <20250916160027.GK12516@e132581.arm.com> <20250916164854.GM12516@e132581.arm.com> <42f1c98c-1432-47bb-9203-e878f011ff6e@linux.dev> <20250916171702.GO12516@e132581.arm.com> From: Suzuki K Poulose In-Reply-To: <20250916171702.GO12516@e132581.arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 16/09/2025 18:17, Leo Yan wrote: > On Tue, Sep 16, 2025 at 12:51:11PM -0400, Sean Anderson wrote: >> On 9/16/25 12:48, Leo Yan wrote: >>> On Tue, Sep 16, 2025 at 12:14:40PM -0400, Sean Anderson wrote: >>> >>> [...] >>> >>>>> Could you check if the drafted patch below looks good to you? If so, I >>>> >>>> As stated above I disagree with a half-hearted removal. If you want to do that, >>>> then I will resend v2 done with an rcu list and you can make your own follow-up. >>> >>> It is fine to disagree, but please don't resend v2 :) >>> >>> We have plan to refactor locking in CoreSight driver, I will try my >>> best to avoid adding new lock unless with a strong reason. >> >> As said above it will be done with an rcu list, so no new lock. >> >> Or I can do this patch but stick the notifier block in csdev as suggested by Suzuki. > > I am fine for adding the notifier block in csdev. > > Suzuki, could you confirm if this is the right way to move forward? Yes, if we are planning to keep a csdev panic_ops, why not stick in the notifier there, rather than splitting it between core code and drivers. Suzuki > > Thanks, > Leo