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=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 EA62CC3A5A1 for ; Thu, 22 Aug 2019 22:19:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99A2620578 for ; Thu, 22 Aug 2019 22:19:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gcodsO2Y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393934AbfHVWTU (ORCPT ); Thu, 22 Aug 2019 18:19:20 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:36858 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393795AbfHVWTU (ORCPT ); Thu, 22 Aug 2019 18:19:20 -0400 Received: by mail-pf1-f193.google.com with SMTP id w2so4918671pfi.3; Thu, 22 Aug 2019 15:19:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=hXggJeNk5DyrlR3Ykl3KL8qzqxi9q3v2FlHbbm7gWl4=; b=gcodsO2YQzJBlOe/tqRER49vskORqFAXiBa1KeZHCmfBhmQuoSTUgEEDlseqTRrozC ZCX4pQ2/HzMS8u7wK/3IhDmPuZLJsA2dA+KxrfgQTxvGgUAhoOvkfxkweoyuFWvazp4l +CKppRl9fbh0aQYajG7t1zjmfXkyBacCaxgQj9Cjw6hQkeN7Y3xVLi9AyOlsaTS3hz86 7faGt5v1x1ksPRwpuVjRI+MqXhFf4ocatQ5RA6dxEVV/CnX4Q8eJaFzp/6gANJIj9DV0 G4ENe6IJ5xRJVBIV+jGRdXYffP6pNZrzy60LTF4/jChAZ4NSVpmPPJDOJqAq1LPwE9UE h1Hg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=hXggJeNk5DyrlR3Ykl3KL8qzqxi9q3v2FlHbbm7gWl4=; b=BfThCx4Cg8cSzlwiW8lGUqAgKhqtOfiQgHlIaAvVyCnbNv0B3Hd9oq0k7Hg2ihzeUq zs6Xhoo412m9/q3XWtrDf6GYWPjzD49KDmZhj0oKYZuG1Mn085qjCneU7+LQzA/ZbOFl Ln/NtKFcKt5NIsAYDEw5/Ej0s2/P2oO2DHy0RLbySUIrCoPV3vSzAhsDVGrUlTZZWaRO UrUk898cdpDnfo6MBwIu5ug3k2l78+CKOfjnduOefErYiy+/3+u9ocfc2cCnYckIVtbT quDKCBmJOmFq+rVpi8Id0SO6F9+lSqxZNnES1fubG6U66Qis8bWbvKGT5c7r014y8DGT bo1g== X-Gm-Message-State: APjAAAVGSiCSW4o39NX1NKhVLxkyfwzzX4zVeQENPgKUH9L8+l1ZD2L+ YzyXxTglzuZE1PzzlLlcUgI= X-Google-Smtp-Source: APXvYqwo/P3Ukfyvj1z2aTJyxTAhQuVP60XXCeDNBl2fvSuHQxBq1pZ1a4s8TltSNYeKNuJPWj3qAQ== X-Received: by 2002:a63:ee08:: with SMTP id e8mr1287128pgi.70.1566512359236; Thu, 22 Aug 2019 15:19:19 -0700 (PDT) Received: from localhost.localdomain ([221.155.202.134]) by smtp.gmail.com with ESMTPSA id k3sm435624pfg.23.2019.08.22.15.19.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Aug 2019 15:19:18 -0700 (PDT) Date: Fri, 23 Aug 2019 07:19:14 +0900 From: Suwan Kim To: Greg KH Cc: shuah@kernel.org, valentina.manea.m@gmail.com, stern@rowland.harvard.edu, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/2] usbip: Skip DMA mapping and unmapping for urb at vhci Message-ID: <20190822221912.GA5004@localhost.localdomain> References: <20190808155435.10050-1-suwan.kim027@gmail.com> <20190808155435.10050-2-suwan.kim027@gmail.com> <20190822164011.GA7093@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190822164011.GA7093@kroah.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 22, 2019 at 09:40:11AM -0700, Greg KH wrote: > On Fri, Aug 09, 2019 at 12:54:34AM +0900, Suwan Kim wrote: > > vhci doesn’t do DMA for remote device. Actually, the real DMA > > operation is done by network card driver. vhci just passes virtual > > address of the buffer to the network stack, so vhci doesn’t use and > > need dma address of the buffer of the URB. > > > > But HCD provides DMA mapping and unmapping function by default. > > Moreover, it causes unnecessary DMA mapping and unmapping which > > will be done again at the NIC driver and it wastes CPU cycles. > > So, implement map_urb_for_dma and unmap_urb_for_dma function for > > vhci in order to skip the DMA mapping and unmapping procedure. > > > > When it comes to supporting SG for vhci, it is useful to use native > > SG list (urb->num_sgs) instead of mapped SG list because DMA mapping > > fnuction can adjust the number of SG list (urb->num_mapped_sgs). > > And vhci_map_urb_for_dma() prevents isoc pipe from using SG as > > hcd_map_urb_for_dma() does. > > > > Signed-off-by: Suwan Kim > > Can you please redo this patch based on my usb-next branch that has > Christoph's DMA changes in it? It should make your change much simpler > and smaller. > > Please do that and resend the whole series. I just sent v6 patch. And I discarded patch1 and patch1 is no longer needed because vhci doesn't set set HCD_DMA flag that is introduced by Christoph's patch. So I sent only patch 2 as v6. Regards Suwan Kim