From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 531D515B0FE; Wed, 24 Jul 2024 15:36:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721835389; cv=none; b=PsIjjwWeF2hOVJlVEQwUDJk6P/ljVmeF+mNpAsPTTRwh2dnmGZN9uJOc8rIti3blLmhWD/wlkkCjSQ78b0a9GpiMa8GIO1YOvZuddBbbXIrlOEA4HimI5zxIAxHbrKQsLBerMN0ylSJUERqWbvitdenAtPdhjeZWLJ9d4hLbnjY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721835389; c=relaxed/simple; bh=dy+PiHf/gs6ghVGg6izoOkhmxgnHq4Gzf3BWbR5h3yg=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=LKy+PrXRg2Qv5puM7ishlrk3/d4o37tnOUV048CrW2VuPdVlh+sW8gTJgdcAUIpUq6A/cHn7qiESRDbDU7j86JLFZL0yfH61/jVTmJ/yQ3ZszQYNHB7YLcrK2LE1QLCUa7misUBaVVCmTnKxwGjBdO+pdejFTucXXRXH7qVLx8w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iA/e9ota; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iA/e9ota" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E885BC32782; Wed, 24 Jul 2024 15:36:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721835389; bh=dy+PiHf/gs6ghVGg6izoOkhmxgnHq4Gzf3BWbR5h3yg=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=iA/e9otaw6Mwui8yoHfDbxojScfPoSU1evarFxgtCOhu9saIA1/odP+gPRWkX+k1B QBHV2K1fdZz0UuMEdEhdGKmT+XKJE90VWxjhCP8cUrHAGlt/EnLqMt8kjZV975WVIQ CkMYGVdIZ8Jnf4OXTnFv3K7dFscf1cFRq4vHVuV/qr+8r05Z+QYNYkgXclnYyrTnKL p0VPRuZZweuocuemEnZ/S+3sGVLjdjl47C002ObSWsK2Y4pNPhQJqweFai3ku9t6b4 dfovRNHm+/YvvUVL2CsphUEZMUhzHG8/NVvWCcjnbKbhQC3hQxO9UZrkOMKOucC1qC uybwCfubFRwnQ== Date: Wed, 24 Jul 2024 10:36:27 -0500 From: Bjorn Helgaas To: Alejandro Lucero Palau Cc: Wei Huang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, netdev@vger.kernel.org, Jonathan.Cameron@huawei.com, corbet@lwn.net, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, alex.williamson@redhat.com, gospo@broadcom.com, michael.chan@broadcom.com, ajit.khaparde@broadcom.com, somnath.kotur@broadcom.com, andrew.gospodarek@broadcom.com, manoj.panicker2@amd.com, Eric.VanTassell@amd.com, vadim.fedorenko@linux.dev, horms@kernel.org, bagasdotme@gmail.com, bhelgaas@google.com Subject: Re: [PATCH V3 03/10] PCI/TPH: Add pci=notph to prevent use of TPH Message-ID: <20240724153627.GA800043@bhelgaas> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jul 24, 2024 at 03:45:34PM +0100, Alejandro Lucero Palau wrote: > On 7/17/24 21:55, Wei Huang wrote: > > TLP headers with incorrect steering tags (e.g. caused by buggy driver) > > can potentially cause issues when the system hardware consumes the tags. > > Provide a kernel option, with related helper functions, to completely > > prevent TPH from being enabled. > > Maybe rephrase it for including a potential buggy device, including the cpu. > > Also, what about handling this with a no-tph-allow device list instead of a > generic binary option for the whole system? > > Foreseeing some buggy or poor-performance implementations, or specific use > cases where it could be counterproductive, maybe supporting both options. Makes sense if/when we need it. IMO no point in adding an empty list of known-broken devices.