From patchwork Mon Jun 17 03:03:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10997857 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 43A2017F0 for ; Mon, 17 Jun 2019 03:06:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 353B028715 for ; Mon, 17 Jun 2019 03:06:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2791C2880B; Mon, 17 Jun 2019 03:06:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D432528715 for ; Mon, 17 Jun 2019 03:06:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727532AbfFQDG0 (ORCPT ); Sun, 16 Jun 2019 23:06:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58264 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727383AbfFQDG0 (ORCPT ); Sun, 16 Jun 2019 23:06:26 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E031E307D859; Mon, 17 Jun 2019 03:06:25 +0000 (UTC) Received: from localhost (ovpn-8-18.pek2.redhat.com [10.72.8.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 19CAA5884C; Mon, 17 Jun 2019 03:06:09 +0000 (UTC) From: Ming Lei To: linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: James Bottomley , Bart Van Assche , Hannes Reinecke , Christoph Hellwig , Jim Gill , Cathy Avery , "Ewan D . Milne" , Brian King , James Smart , "Juergen E . Fischer" , Michael Schmitz , Finn Thain , Greg Kroah-Hartman , devel@driverdev.osuosl.org, linux-usb@vger.kernel.org, Dan Carpenter , Benjamin Block , Ming Lei , Kim Bradley Subject: [PATCH V4 09/16] staging: rtsx: use sg helper to operate scatterlist Date: Mon, 17 Jun 2019 11:03:42 +0800 Message-Id: <20190617030349.26415-10-ming.lei@redhat.com> In-Reply-To: <20190617030349.26415-1-ming.lei@redhat.com> References: <20190617030349.26415-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Mon, 17 Jun 2019 03:06:26 +0000 (UTC) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. Cc: Kim Bradley Cc: devel@driverdev.osuosl.org Cc: Greg Kroah-Hartman Signed-off-by: Ming Lei --- drivers/staging/rts5208/rtsx_transport.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/staging/rts5208/rtsx_transport.c b/drivers/staging/rts5208/rtsx_transport.c index 8277d7895608..407c9079b052 100644 --- a/drivers/staging/rts5208/rtsx_transport.c +++ b/drivers/staging/rts5208/rtsx_transport.c @@ -63,6 +63,8 @@ unsigned int rtsx_stor_access_xfer_buf(unsigned char *buffer, struct scatterlist *sg = (struct scatterlist *)scsi_sglist(srb) + *index; + if (sg_is_chain(sg)) + sg = sg_chain_ptr(sg); /* * This loop handles a single s-g list entry, which may @@ -86,7 +88,7 @@ unsigned int rtsx_stor_access_xfer_buf(unsigned char *buffer, /* Transfer continues to next s-g entry */ *offset = 0; ++*index; - ++sg; + sg = sg_next(sg); } while (sglen > 0) {