From patchwork Thu Aug 29 23:05:41 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 2851649 Return-Path: X-Original-To: patchwork-linux-arm@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 B0C9BC0AB5 for ; Thu, 29 Aug 2013 23:07:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B288220503 for ; Thu, 29 Aug 2013 23:07:54 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A660720502 for ; Thu, 29 Aug 2013 23:07:53 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VFBJD-0004Rv-7H; Thu, 29 Aug 2013 23:07:23 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VFBIx-0004EF-20; Thu, 29 Aug 2013 23:07:07 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VFBIP-00049g-34 for linux-arm-kernel@lists.infradead.org; Thu, 29 Aug 2013 23:06:34 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id r7TN5xvY010553; Thu, 29 Aug 2013 18:06:00 -0500 Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id r7TN5xIC020702; Thu, 29 Aug 2013 18:05:59 -0500 Received: from dlep32.itg.ti.com (157.170.170.100) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.2.342.3; Thu, 29 Aug 2013 18:05:58 -0500 Received: from joel-laptop.itg.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id r7TN5j0a030581; Thu, 29 Aug 2013 18:05:57 -0500 From: Joel Fernandes To: Sekhar Nori , Matt Porter , Vinod Koul , Dan Williams , Russell King , Sricharan R Subject: [PATCH v4 2/6] dma: edma: Write out and handle MAX_NR_SG at a given time Date: Thu, 29 Aug 2013 18:05:41 -0500 Message-ID: <1377817545-18015-3-git-send-email-joelf@ti.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1377817545-18015-1-git-send-email-joelf@ti.com> References: <1377817545-18015-1-git-send-email-joelf@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130829_190633_318226_DDA1C979 X-CRM114-Status: GOOD ( 14.14 ) X-Spam-Score: -9.4 (---------) Cc: Linux DaVinci Kernel List , Joel Fernandes , Koen Kooi , Linux MMC List , Linux Kernel Mailing List , Franklin Cooper , Linux OMAP List , Linux ARM Kernel List X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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_NR_SG if they are greater than MAX_NR_SG. 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_NR_SG), 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, 53 insertions(+), 26 deletions(-) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index e522ad5..732829b 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 processed; struct edmacc_param pset[0]; }; @@ -104,22 +105,34 @@ 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; - - if (!vdesc) { - echan->edesc = NULL; - return; + struct device *dev = echan->vchan.chan.device->dev; + int i, j, left, nslots; + + /* If either we processed all psets or we're still not started */ + if (!echan->edesc || + echan->edesc->pset_nr == echan->edesc->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; - echan->edesc = edesc = to_edma_desc(&vdesc->tx); + /* Find out how many left */ + left = edesc->pset_nr - edesc->processed; + nslots = min(MAX_NR_SG, left); /* 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 < nslots; i++) { + j = i + edesc->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" @@ -132,24 +145,31 @@ 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 != (nslots - 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->processed += nslots; + + edma_resume(echan->ch_num); + + if (edesc->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) @@ -368,19 +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->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);