From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=mHtA=UQ=vger.kernel.org=linux-usb-owner@kernel.org>
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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 1DC65C31E53
	for <linux-usb@archiver.kernel.org>; Mon, 17 Jun 2019 08:27:59 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id 0041B204FD
	for <linux-usb@archiver.kernel.org>; Mon, 17 Jun 2019 08:27:58 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727998AbfFQI16 (ORCPT <rfc822;linux-usb@archiver.kernel.org>);
        Mon, 17 Jun 2019 04:27:58 -0400
Received: from verein.lst.de ([213.95.11.211]:34073 "EHLO newverein.lst.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1727906AbfFQI1f (ORCPT <rfc822;linux-usb@vger.kernel.org>);
        Mon, 17 Jun 2019 04:27:35 -0400
Received: by newverein.lst.de (Postfix, from userid 2407)
        id BDECB68CEC; Mon, 17 Jun 2019 10:27:06 +0200 (CEST)
Date:   Mon, 17 Jun 2019 10:27:06 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Ming Lei <ming.lei@redhat.com>
Cc:     linux-scsi@vger.kernel.org,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        James Bottomley <James.Bottomley@HansenPartnership.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Hannes Reinecke <hare@suse.com>,
        Christoph Hellwig <hch@lst.de>, Jim Gill <jgill@vmware.com>,
        Cathy Avery <cavery@redhat.com>,
        "Ewan D . Milne" <emilne@redhat.com>,
        Brian King <brking@us.ibm.com>,
        James Smart <james.smart@broadcom.com>,
        "Juergen E . Fischer" <fischer@norbit.de>,
        Michael Schmitz <schmitzmic@gmail.com>,
        Finn Thain <fthain@telegraphics.com.au>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        devel@driverdev.osuosl.org, linux-usb@vger.kernel.org,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Benjamin Block <bblock@linux.ibm.com>,
        Kim Bradley <kim.jamie.bradley@gmail.com>
Subject: Re: [PATCH V4 09/16] staging: rtsx: use sg helper to operate
 scatterlist
Message-ID: <20190617082706.GI7455@lst.de>
References: <20190617030349.26415-1-ming.lei@redhat.com> <20190617030349.26415-10-ming.lei@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190617030349.26415-10-ming.lei@redhat.com>
User-Agent: Mutt/1.5.17 (2007-11-01)
Sender: linux-usb-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-usb.vger.kernel.org>
X-Mailing-List: linux-usb@vger.kernel.org

On Mon, Jun 17, 2019 at 11:03:42AM +0800, Ming Lei wrote:
> Use the scatterlist iterators and remove direct indexing of the
> scatterlist array.
> 
> This way allows us to pre-allocate one small scatterlist, which can be
> chained with one runtime allocated scatterlist if the pre-allocated one
> isn't enough for the whole request.

The scatterlist handling here looks completely bogus, it really
needs to stop using the index and switch to proper sg_next-based
iteration.