linux-kernel - [PATCH] ARM: EDMA: Fix clearing of unused list for DT DMA resources

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <1377570387-10391-1-git-send-email-joelf@ti.com>
Date:	Mon, 26 Aug 2013 21:26:27 -0500
From:	Joel Fernandes <joelf@...com>
To:	Sekhar Nori <nsekhar@...com>
CC:	Linux OMAP List <linux-omap@...r.kernel.org>,
	Linux ARM Kernel List <linux-arm-kernel@...ts.infradead.org>,
	Linux DaVinci Kernel List 
	<davinci-linux-open-source@...ux.davincidsp.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Pantel Antoniou <panto@...oniou-consulting.com>,
	Joel Fernandes <joelf@...com>
Subject: [PATCH] ARM: EDMA: Fix clearing of unused list for DT DMA resources

HWMOD removal for MMC is breaking edma_start as the events are being manually
triggered due to unused channel list not being clear.

This patch fixes the issue, by reading the "dmas" property from the DT node if
it exists and clearing the bits in the unused channel list. For this purpose
we use the of_* helpers to parse the arguments in the dmas phandle list.

Reviewed-by: Sekhar Nori <nsekhar@...com>
Reported-by: Balaji T K <balajitk@...com>
Cc: Pantel Antoniou <panto@...oniou-consulting.com>
Signed-off-by: Joel Fernandes <joelf@...com>
---
Changes since v1, in v2 and v3:
- Reduced indentation of non-of case by returning from of-case
- Using of_* helpers for parsing

Note:
This patch should go into the merge window as it is a critical bug fix.

 arch/arm/common/edma.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index 39ad030..43c7b22 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -560,14 +560,33 @@ 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;
+
+			ctlr = EDMA_CTLR(dma_spec.args[0]);
+			clear_bit(EDMA_CHAN_SLOT(dma_spec.args[0]),
+				  edma_cc[ctlr]->edma_unused);
+		}
+		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);
 		}
 	}
 
-- 
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/