Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754482Ab3IZV4h (ORCPT ); Thu, 26 Sep 2013 17:56:37 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:55742 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754427Ab3IZV4f (ORCPT ); Thu, 26 Sep 2013 17:56:35 -0400 From: Joel Fernandes To: Sekhar Nori , Vinod Koul , Dan Williams CC: Linux OMAP List , Linux ARM Kernel List , Linux DaVinci Kernel List , Linux Kernel Mailing List , Linux MMC List , Tony Lindgren , Olof Johansson , Nishanth Menon , Pantel Antoniou , Jason Kridner , Koen Kooi , Joel Fernandes Subject: [PATCH v3] ARM: EDMA: Fix clearing of unused list for DT DMA resources Date: Thu, 26 Sep 2013 16:55:46 -0500 Message-ID: <1380232546-821-1-git-send-email-joelf@ti.com> X-Mailer: git-send-email 1.8.1.2 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: 4305 Lines: 122 HWMOD removal for MMC is breaking edma_start as the events are being manually triggered due to unused channel list not being clear. The above issue is fixed by reading the "dmas" property from the DT node if it exists and clearing the bits in the unused channel list if the dma controller used by any device is EDMA. For this purpose we use the of_* helpers to parse the arguments in the dmas phandle list. Also introduced is a minor clean up of a checkpatch error in old code. Reviewed-by: Sekhar Nori Reported-by: Balaji T K Cc: Sekhar Nori Cc: Tony Lindgren Cc: Olof Johansson Cc: Nishanth Menon Cc: Pantel Antoniou Cc: Jason Kridner Cc: Koen Kooi Signed-off-by: Joel Fernandes --- Just resending this patch after discussing with Sekhar and Olof. AM335x is being booted by many users such as the beaglebone community. DT is the only boot method available for all these users. EDMA is required for the operation for many common peripherals in AM335x SoC such as McASP, MMC and Crypto. Although EDMA DT nodes are going in only for 3.13, in reality the kernel has been used for more than a year with EDMA code and out of tree EDMA DTS patches. Hence though the DT nodes are still not in mainline, this patch can be still be considered a critical fix as such and it would be great if it could be included in 3.12-rc release. Thanks. More details about why this broke an existing feature folks were using: Previously the DMA resources for platform devices were being populated through HWMOD, however with the recent clean ups with HWMOD, this data has been moved to Device tree. The EDMA code though is not aware of this so it fails to fetch the DMA resources correctly which it needs to prepare the unused channel list (basically doesn't properly clear the channels that are in use, in the unused list). arch/arm/common/edma.c | 38 +++++++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 7 deletions(-) diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c index 117f955..8e1a024 100644 --- a/arch/arm/common/edma.c +++ b/arch/arm/common/edma.c @@ -269,6 +269,11 @@ static const struct edmacc_param dummy_paramset = { .ccnt = 1, }; +static const struct of_device_id edma_of_ids[] = { + { .compatible = "ti,edma3", }, + {} +}; + /*****************************************************************************/ static void map_dmach_queue(unsigned ctlr, unsigned ch_no, @@ -560,14 +565,38 @@ static int reserve_contiguous_slots(int ctlr, unsigned int id, static int prepare_unused_channel_list(struct device *dev, void *data) { struct platform_device *pdev = to_platform_device(dev); - int i, ctlr; + int i, count, ctlr; + struct of_phandle_args dma_spec; + if (dev->of_node) { + count = of_property_count_strings(dev->of_node, "dma-names"); + if (count < 0) + return 0; + for (i = 0; i < count; i++) { + if (of_parse_phandle_with_args(dev->of_node, "dmas", + "#dma-cells", i, + &dma_spec)) + continue; + + if (!of_match_node(edma_of_ids, dma_spec.np)) { + of_node_put(dma_spec.np); + continue; + } + + clear_bit(EDMA_CHAN_SLOT(dma_spec.args[0]), + edma_cc[0]->edma_unused); + of_node_put(dma_spec.np); + } + return 0; + } + + /* For non-OF case */ for (i = 0; i < pdev->num_resources; i++) { if ((pdev->resource[i].flags & IORESOURCE_DMA) && (int)pdev->resource[i].start >= 0) { ctlr = EDMA_CTLR(pdev->resource[i].start); clear_bit(EDMA_CHAN_SLOT(pdev->resource[i].start), - edma_cc[ctlr]->edma_unused); + edma_cc[ctlr]->edma_unused); } } @@ -1762,11 +1791,6 @@ static int edma_probe(struct platform_device *pdev) return 0; } -static const struct of_device_id edma_of_ids[] = { - { .compatible = "ti,edma3", }, - {} -}; - static struct platform_driver edma_driver = { .driver = { .name = "edma", -- 1.8.1.2 -- 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/