From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 036FAC433C1 for ; Sat, 27 Mar 2021 04:51:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7C9561A1A for ; Sat, 27 Mar 2021 04:51:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229611AbhC0Eu7 (ORCPT ); Sat, 27 Mar 2021 00:50:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:36600 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbhC0EuZ (ORCPT ); Sat, 27 Mar 2021 00:50:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 46B92619E4; Sat, 27 Mar 2021 04:50:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616820624; bh=Z0tIGB2gR7iDVQpCU37gBJN0QgIrfaYJ/ZrhmVD8cig=; h=Date:From:To:Cc:Subject:From; b=OQGqM6eYLmHBEaCcvytWwaDcihGCee1Wo6z02LCGf7PKstKQub4Rez35nfO8VW7i3 vUC9ad5U3fVy0GYvHZq/JkAA+EWdPDoGgr0nPltgIxP25Udq/jUUPObmMBglJYiL6t 1BYbvo9gtlvEFrz75cWhIb3sHW1T0ERAROUsybiu4bx35CQY4C5a6mEnOyWZRO3kMv p6KiE/jrwhbkt8opD2a9thhhWh4myXcsrgmzhC5CzD/plfV4vveDkJzhRYYtWYodoB U+8IQusBNWpWHukylyN/U6oUvgb4y2d5e6dn6W+PRXqI7YRB+ChQOv3Yd9yDPDLD05 Vu8ZduwfKJRlg== Date: Sat, 27 Mar 2021 12:50:16 +0800 From: Peter Chen To: Pawel Laszczak Cc: linux-usb@vger.kernel.org Subject: About use case of cdns3-pci-wrap.c Message-ID: <20210327045016.GD28870@b29397-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi Pawel, >From the code of this file, it seems the controller driver is running at PC side, but the hardware controller is at verification board, the two sides are connected by PCIe. Am I right? If I am right, the memory (eg, the TRB ring address and data buffer) the hardware try to visit is at PC side, but how controller visits PC memory since the TRB ring address is allocated dynamically by controller device driver running at PC? How the local bus arbiter knows it is PCIe address at verification board? Besides, could the upstream code run this IP verification solution through PCIe without changing any code? Thanks. -- Thanks, Peter Chen