From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Lei 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> References: <20190617030349.26415-1-ming.lei@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190617030349.26415-1-ming.lei@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" To: linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: Michael Schmitz , devel@driverdev.osuosl.org, Hannes Reinecke , Benjamin Block , Bart Van Assche , Greg Kroah-Hartman , linux-usb@vger.kernel.org, James Smart , "Ewan D . Milne" , Jim Gill , James Bottomley , Oliver Neukum , Brian King , Finn Thain , "Juergen E . Fischer" , Ming Lei , Christoph Hellwig , Dan Carpenter List-Id: linux-scsi@vger.kernel.org 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 Cc: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org Signed-off-by: Ming Lei --- 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