From patchwork Sun Jul 21 06:58:08 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 2830889 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3EDF1C0319 for ; Sun, 21 Jul 2013 06:59:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 48A9520168 for ; Sun, 21 Jul 2013 06:59:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42B872013C for ; Sun, 21 Jul 2013 06:59:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753659Ab3GUG7H (ORCPT ); Sun, 21 Jul 2013 02:59:07 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:50296 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753503Ab3GUG6v (ORCPT ); Sun, 21 Jul 2013 02:58:51 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id r6L6wBvg004779; Sun, 21 Jul 2013 01:58:11 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id r6L6wBVF031638; Sun, 21 Jul 2013 01:58:11 -0500 Received: from dlelxv22.itg.ti.com (172.17.1.197) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.2.342.3; Sun, 21 Jul 2013 01:58:10 -0500 Received: from joel-laptop.itg.ti.com (h56-25.vpn.ti.com [172.24.56.25]) by dlelxv22.itg.ti.com (8.13.8/8.13.8) with ESMTP id r6L6w8Qa011377; Sun, 21 Jul 2013 01:58:10 -0500 From: Joel Fernandes To: Tony Lindgren , Sekhar Nori , Santosh Shilimkar , Sricharan R , Rajendra Nayak , Lokesh Vutla , Matt Porter , Grant Likely , Rob Herring , Vinod Koul , Dan Williams , Mark Brown , Benoit Cousson , Russell King , Arnd Bergmann , Balaji TK , Gururaja Hebbar , Chris Ball , Jason Kridner CC: Linux OMAP List , Linux ARM Kernel List , Linux DaVinci Kernel List , Linux Kernel Mailing List , Linux MMC List , Joel Fernandes Subject: [RFC 2/5] dma: edma: Write out and handle MAX_SG_NR at a given time Date: Sun, 21 Jul 2013 01:58:08 -0500 Message-ID: <1374389888-32538-1-git-send-email-joelf@ti.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-8.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Process SG-elements in batches of MAX_SG_NR if they are greater than MAX_SG_NR. Due to this, at any given time only those many slots will be used in the given channel no matter how long the scatter list is. We keep track of how much has been written inorder to process the next batch of elements in the scatter-list and detect completion. For such intermediate transfer completions (one batch of MAX_SG_NR), make use of pause and resume functions instead of start and stop when such intermediate transfer is in progress or completed as we donot want to clear any pending events. Signed-off-by: Joel Fernandes --- drivers/dma/edma.c | 79 +++++++++++++++++++++++++++++++++++----------------- 1 file changed, 54 insertions(+), 25 deletions(-) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 9b9954e..0e7ed79 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -56,6 +56,7 @@ struct edma_desc { struct list_head node; int absync; int pset_nr; + int total_processed; struct edmacc_param pset[0]; }; @@ -105,22 +106,36 @@ static void edma_desc_free(struct virt_dma_desc *vdesc) /* Dispatch a queued descriptor to the controller (caller holds lock) */ static void edma_execute(struct edma_chan *echan) { - struct virt_dma_desc *vdesc = vchan_next_desc(&echan->vchan); + struct virt_dma_desc *vdesc; struct edma_desc *edesc; - int i; + struct device *dev = echan->vchan.chan.device->dev; - if (!vdesc) { - echan->edesc = NULL; - return; + int i, j, total_left, total_process; + + /* If either we processed all psets or we're still not started */ + if (!echan->edesc || + echan->edesc->pset_nr == echan->edesc->total_processed) { + /* Get next vdesc */ + vdesc = vchan_next_desc(&echan->vchan); + if (!vdesc) { + echan->edesc = NULL; + return; + } + list_del(&vdesc->node); + echan->edesc = to_edma_desc(&vdesc->tx); } - list_del(&vdesc->node); + edesc = echan->edesc; + + /* Find out how many left */ + total_left = edesc->pset_nr - edesc->total_processed; + total_process = total_left > MAX_NR_SG ? MAX_NR_SG : total_left; - echan->edesc = edesc = to_edma_desc(&vdesc->tx); /* Write descriptor PaRAM set(s) */ - for (i = 0; i < edesc->pset_nr; i++) { - edma_write_slot(echan->slot[i], &edesc->pset[i]); + for (i = 0; i < total_process; i++) { + j = i + edesc->total_processed; + edma_write_slot(echan->slot[i], &edesc->pset[j]); dev_dbg(echan->vchan.chan.device->dev, "\n pset[%d]:\n" " chnum\t%d\n" @@ -133,24 +148,31 @@ static void edma_execute(struct edma_chan *echan) " bidx\t%08x\n" " cidx\t%08x\n" " lkrld\t%08x\n", - i, echan->ch_num, echan->slot[i], - edesc->pset[i].opt, - edesc->pset[i].src, - edesc->pset[i].dst, - edesc->pset[i].a_b_cnt, - edesc->pset[i].ccnt, - edesc->pset[i].src_dst_bidx, - edesc->pset[i].src_dst_cidx, - edesc->pset[i].link_bcntrld); + j, echan->ch_num, echan->slot[i], + edesc->pset[j].opt, + edesc->pset[j].src, + edesc->pset[j].dst, + edesc->pset[j].a_b_cnt, + edesc->pset[j].ccnt, + edesc->pset[j].src_dst_bidx, + edesc->pset[j].src_dst_cidx, + edesc->pset[j].link_bcntrld); /* Link to the previous slot if not the last set */ - if (i != (edesc->pset_nr - 1)) + if (i != (total_process - 1)) edma_link(echan->slot[i], echan->slot[i+1]); /* Final pset links to the dummy pset */ else edma_link(echan->slot[i], echan->ecc->dummy_slot); } - edma_start(echan->ch_num); + edesc->total_processed += total_process; + + edma_resume(echan->ch_num); + + if (edesc->total_processed <= MAX_NR_SG) { + dev_dbg(dev, "first transfer starting %d\n", echan->ch_num); + edma_start(echan->ch_num); + } } static int edma_terminate_all(struct edma_chan *echan) @@ -366,19 +388,26 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data) struct edma_desc *edesc; unsigned long flags; - /* Stop the channel */ - edma_stop(echan->ch_num); + /* Pause the channel */ + edma_pause(echan->ch_num); switch (ch_status) { case DMA_COMPLETE: - dev_dbg(dev, "transfer complete on channel %d\n", ch_num); - spin_lock_irqsave(&echan->vchan.lock, flags); edesc = echan->edesc; if (edesc) { + if (edesc->total_processed == edesc->pset_nr) { + dev_dbg(dev, "transfer complete." \ + " stopping channel %d\n", ch_num); + edma_stop(echan->ch_num); + vchan_cookie_complete(&edesc->vdesc); + } else { + dev_dbg(dev, "Intermediate transfer complete" \ + " on channel %d\n", ch_num); + } + edma_execute(echan); - vchan_cookie_complete(&edesc->vdesc); } spin_unlock_irqrestore(&echan->vchan.lock, flags);