Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754690Ab3HEQST (ORCPT ); Mon, 5 Aug 2013 12:18:19 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:39298 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754362Ab3HEQQG (ORCPT ); Mon, 5 Aug 2013 12:16:06 -0400 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 , Olof Johansson , 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: [PATCH v3 01/12] dma: edma: Setup parameters to DMA MAX_NR_SG at a time Date: Mon, 5 Aug 2013 11:14:46 -0500 Message-ID: <1375719297-12871-2-git-send-email-joelf@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1375719297-12871-1-git-send-email-joelf@ti.com> References: <1375719297-12871-1-git-send-email-joelf@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2212 Lines: 69 Changes are made here for configuring existing parameters to support DMA'ing them out in batches as needed. Also allocate as many as slots as needed by the SG list, but not more than MAX_NR_SG. Then these slots will be reused accordingly. For ex, if MAX_NR_SG=10, and number of SG entries is 40, still only 10 slots will be allocated to DMA the entire SG list of size 40. Signed-off-by: Joel Fernandes --- drivers/dma/edma.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 5f3e532..7b0853c 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -222,9 +222,9 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( enum dma_slave_buswidth dev_width; u32 burst; struct scatterlist *sg; - int i; int acnt, bcnt, ccnt, src, dst, cidx; int src_bidx, dst_bidx, src_cidx, dst_cidx; + int i, num_slots_needed; if (unlikely(!echan || !sgl || !sg_len)) return NULL; @@ -262,8 +262,11 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( edesc->pset_nr = sg_len; - for_each_sg(sgl, sg, sg_len, i) { - /* Allocate a PaRAM slot, if needed */ + /* Allocate a PaRAM slot, if needed */ + + num_slots_needed = sg_len > MAX_NR_SG ? MAX_NR_SG : sg_len; + + for (i = 0; i < num_slots_needed; i++) { if (echan->slot[i] < 0) { echan->slot[i] = edma_alloc_slot(EDMA_CTLR(echan->ch_num), @@ -273,6 +276,10 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( return NULL; } } + } + + /* Configure PaRAM sets for each SG */ + for_each_sg(sgl, sg, sg_len, i) { acnt = dev_width; @@ -330,6 +337,7 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( /* Configure A or AB synchronized transfers */ if (edesc->absync) edesc->pset[i].opt |= SYNCDIM; + /* If this is the last set, enable completion interrupt flag */ if (i == sg_len - 1) edesc->pset[i].opt |= TCINTEN; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/