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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 12208C282DD for ; Sat, 20 Apr 2019 03:49:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D477F208C0 for ; Sat, 20 Apr 2019 03:49:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727614AbfDTDsZ (ORCPT ); Fri, 19 Apr 2019 23:48:25 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:48522 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725911AbfDTDsZ (ORCPT ); Fri, 19 Apr 2019 23:48:25 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id DBC377E5CE5585331887; Sat, 20 Apr 2019 11:48:22 +0800 (CST) Received: from [127.0.0.1] (10.63.139.185) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.408.0; Sat, 20 Apr 2019 11:48:12 +0800 Subject: Re: [PATCH] lib: scatterlist: Fix to support no mapped sg To: Robert Jarzmik References: <1555581006-153458-1-git-send-email-wangzhou1@hisilicon.com> <871s1ymg1k.fsf@belgarion.home> CC: , , From: Zhou Wang Message-ID: <5CBA967C.5010502@hisilicon.com> Date: Sat, 20 Apr 2019 11:48:12 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <871s1ymg1k.fsf@belgarion.home> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.63.139.185] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/4/19 18:43, Robert Jarzmik wrote: > Zhou Wang writes: > >> In function sg_split, the second sg_calculate_split will return -EINVAL >> when in_mapped_nents is 0. >> >> Indeed there is no need to do second sg_calculate_split and sg_split_mapped >> when in_mapped_nents is 0, as in_mapped_nents indicates no mapped entry in >> original sgl. >> >> Signed-off-by: Zhou Wang > That's right. May I know what is the usecase which led you to this fix ? I posted a patchset to support HiSilicon compression engine: https://lkml.org/lkml/2019/1/23/358. As Herber Xu suggested, it should use new crypto acomp API which uses sgl as data input and output. However, our hardware can not handle compress head for input/output data, so I need split input/output sgl firstly which is not mapped sgl. New version of HiSilicon compression engine driver has not been posted to community yet. I will do this later. > > Acked-by: Robert Jarzmik Many thanks for your review, Zhou > > -- > Robert > > . >