From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org ([198.145.29.96]:37455 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755117AbbJ1Rvu (ORCPT ); Wed, 28 Oct 2015 13:51:50 -0400 Received: from [10.228.68.96] (rrcs-67-52-130-30.west.biz.rr.com [67.52.130.30]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: okaya@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 3F716140E9D for ; Wed, 28 Oct 2015 17:51:49 +0000 (UTC) To: linux-pci@vger.kernel.org From: Sinan Kaya Subject: ECRC and Max Read Request Size Message-ID: <56310B34.6000102@codeaurora.org> Date: Wed, 28 Oct 2015 13:51:48 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: I'm seeing two problems with the current PCI framework when it comes to end-to-end CRC (ECRC) and Max Read Request Size. The problem with ECRC is that it blindly enables ECRC generation on devices without checking if it is supported by the entire bus with ECRC=on option. ECRC check can be enabled on all devices but ECRC generation on the root complex and switches needs to be set only if all devices support ECRC checking. I'm thinking of making changes in this area to cover this gap with ECRC=safe option. The other problem I'm seeing is about the maximum read request size. If I choose the PCI bus performance mode, maximum read request size is being limited to the maximum payload size. I'd like to add a new mode where I can have bigger read request size than the maximum payload size. Opinions? -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project