Linux-USB Archive on lore.kernel.org
 help / color / Atom feed
From: Ming Lei <ming.lei@redhat.com>
To: linux-scsi@vger.kernel.org,
	"Martin K . Petersen" <martin.petersen@oracle.com>
Cc: 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>,
	Ming Lei <ming.lei@redhat.com>, Oliver Neukum <oliver@neukum.org>
Subject: [PATCH V4 07/16] usb: image: microtek: use sg helper to operate scatterlist
Date: Mon, 17 Jun 2019 11:03:40 +0800
Message-ID: <20190617030349.26415-8-ming.lei@redhat.com> (raw)
In-Reply-To: <20190617030349.26415-1-ming.lei@redhat.com>

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: Oliver Neukum <oliver@neukum.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/usb/image/microtek.c | 20 ++++++++------------
 drivers/usb/image/microtek.h |  2 +-
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/image/microtek.c b/drivers/usb/image/microtek.c
index 607be1f4fe27..0a57c2cc8e5a 100644
--- a/drivers/usb/image/microtek.c
+++ b/drivers/usb/image/microtek.c
@@ -488,7 +488,6 @@ static void mts_command_done( struct urb *transfer )
 
 static void mts_do_sg (struct urb* transfer)
 {
-	struct scatterlist * sg;
 	int status = transfer->status;
 	MTS_INT_INIT();
 
@@ -500,13 +499,12 @@ static void mts_do_sg (struct urb* transfer)
 		mts_transfer_cleanup(transfer);
         }
 
-	sg = scsi_sglist(context->srb);
-	context->fragment++;
+	context->curr_sg = sg_next(context->curr_sg);
 	mts_int_submit_urb(transfer,
 			   context->data_pipe,
-			   sg_virt(&sg[context->fragment]),
-			   sg[context->fragment].length,
-			   context->fragment + 1 == scsi_sg_count(context->srb) ?
+			   sg_virt(context->curr_sg),
+			   context->curr_sg->length,
+			   sg_is_last(context->curr_sg) ?
 			   mts_data_done : mts_do_sg);
 }
 
@@ -526,22 +524,20 @@ static void
 mts_build_transfer_context(struct scsi_cmnd *srb, struct mts_desc* desc)
 {
 	int pipe;
-	struct scatterlist * sg;
-	
+
 	MTS_DEBUG_GOT_HERE();
 
 	desc->context.instance = desc;
 	desc->context.srb = srb;
-	desc->context.fragment = 0;
 
 	if (!scsi_bufflen(srb)) {
 		desc->context.data = NULL;
 		desc->context.data_length = 0;
 		return;
 	} else {
-		sg = scsi_sglist(srb);
-		desc->context.data = sg_virt(&sg[0]);
-		desc->context.data_length = sg[0].length;
+		desc->context.curr_sg = scsi_sglist(srb);
+		desc->context.data = sg_virt(desc->context.curr_sg);
+		desc->context.data_length = desc->context.curr_sg->length;
 	}
 
 
diff --git a/drivers/usb/image/microtek.h b/drivers/usb/image/microtek.h
index 66685e59241a..7bd5f4639c4a 100644
--- a/drivers/usb/image/microtek.h
+++ b/drivers/usb/image/microtek.h
@@ -21,7 +21,7 @@ struct mts_transfer_context
 	void *data;
 	unsigned data_length;
 	int data_pipe;
-	int fragment;
+	struct scatterlist *curr_sg;
 
 	u8 *scsi_status; /* status returned from ep_response after command completion */
 };
-- 
2.20.1


  parent reply index

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-17  3:03 [PATCH V4 00/16] " Ming Lei
2019-06-17  3:03 ` [PATCH V4 01/16] scsi: vmw_pscsi: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 02/16] scsi: advansys: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 03/16] scsi: lpfc: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 04/16] scsi: mvumi: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 05/16] scsi: ipr: " Ming Lei
2019-06-17  8:24   ` Christoph Hellwig
2019-06-17  8:50     ` Ming Lei
2019-06-17  3:03 ` [PATCH V4 06/16] scsi: pmcraid: " Ming Lei
2019-06-17  8:24   ` Christoph Hellwig
2019-06-17  3:03 ` Ming Lei [this message]
2019-06-17  8:25   ` [PATCH V4 07/16] usb: image: microtek: " Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 08/16] staging: unisys: visorhba: " Ming Lei
2019-06-17  8:25   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 09/16] staging: rtsx: " Ming Lei
2019-06-17  8:27   ` Christoph Hellwig
2019-06-17  9:15     ` Ming Lei
2019-06-17  9:24       ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 10/16] s390: zfcp_fc: " Ming Lei
2019-06-17  8:27   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 11/16] scsi: aha152x: " Ming Lei
2019-06-17  3:35   ` Finn Thain
2019-06-17 23:35     ` Finn Thain
2019-06-18  0:15       ` Ming Lei
2019-06-17  8:28   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 12/16] scsi: imm: " Ming Lei
2019-06-17  8:28   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 13/16] scsi: pcmcia: nsp_cs: " Ming Lei
2019-06-17  8:29   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 14/16] scsi: ppa: " Ming Lei
2019-06-17  8:29   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 15/16] scsi: wd33c93: " Ming Lei
2019-06-17  8:29   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 16/16] NCR5380: Support chained sg lists Ming Lei
2019-06-17  8:30   ` Christoph Hellwig
2019-06-17 23:52 ` [PATCH V4 00/16] use sg helper to operate scatterlist Bart Van Assche

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190617030349.26415-8-ming.lei@redhat.com \
    --to=ming.lei@redhat.com \
    --cc=James.Bottomley@HansenPartnership.com \
    --cc=bblock@linux.ibm.com \
    --cc=brking@us.ibm.com \
    --cc=bvanassche@acm.org \
    --cc=cavery@redhat.com \
    --cc=dan.carpenter@oracle.com \
    --cc=devel@driverdev.osuosl.org \
    --cc=emilne@redhat.com \
    --cc=fischer@norbit.de \
    --cc=fthain@telegraphics.com.au \
    --cc=gregkh@linuxfoundation.org \
    --cc=hare@suse.com \
    --cc=hch@lst.de \
    --cc=james.smart@broadcom.com \
    --cc=jgill@vmware.com \
    --cc=linux-scsi@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=oliver@neukum.org \
    --cc=schmitzmic@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-USB Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-usb/0 linux-usb/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-usb linux-usb/ https://lore.kernel.org/linux-usb \
		linux-usb@vger.kernel.org linux-usb@archiver.kernel.org
	public-inbox-index linux-usb

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-usb


AGPL code for this site: git clone https://public-inbox.org/ public-inbox