diff mbox

[v3] ARM: EDMA: Fix clearing of unused list for DT DMA resources

Message ID 52386733.8010807@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Joel Fernandes Sept. 17, 2013, 2:29 p.m. UTC 
On 09/17/2013 01:05 AM, Sekhar Nori wrote:
[..]
>>> mixed messages. In short, we aim for consistency with situation today,
>>> not tomorrow.
>>
>> What you're asking to do infact breaks consistency with the rest of the code.
> 
> Well, ideally we support second CC even with DT to be consistent all
> around. Since that has not happened, I don't want the code to pretend
> that it it supports the second channel controller with DT that too only
> in parts of code.

Ok, I agree that the bindings don't talk about encoding a controller number in
the channel provided from DT so it shouldn't assume that without binding
updates. Following this suggestion, I've update the patch to the below:

---8<---
From: Joel Fernandes <joelf@ti.com>
Subject: [PATCH v6] 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.

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 <nsekhar@ti.com>
Reported-by: Balaji T K <balajitk@ti.com>
Cc: Pantel Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Joel Fernandes <joelf@ti.com>
---
Changes since initial version:
- Using of_node_put on dma_spec's node pointer.
- Update changelog with minor cleanup information.
- For DT-case, set controller number as 0.
- Reduced indentation of non-of case by returning from of-case
- Using of_* helpers for parsing

 arch/arm/common/edma.c | 38 +++++++++++++++++++++++++++++++-------
 1 file changed, 31 insertions(+), 7 deletions(-)

Comments

Sekhar Nori Sept. 19, 2013, 9:35 a.m. UTC | #1 
On Tuesday 17 September 2013 07:59 PM, Joel Fernandes wrote:
> On 09/17/2013 01:05 AM, Sekhar Nori wrote:
> [..]
>>>> mixed messages. In short, we aim for consistency with situation today,
>>>> not tomorrow.
>>>
>>> What you're asking to do infact breaks consistency with the rest of the code.
>>
>> Well, ideally we support second CC even with DT to be consistent all
>> around. Since that has not happened, I don't want the code to pretend
>> that it it supports the second channel controller with DT that too only
>> in parts of code.
> 
> Ok, I agree that the bindings don't talk about encoding a controller number in
> the channel provided from DT so it shouldn't assume that without binding
> updates. Following this suggestion, I've update the patch to the below:
> 
> ---8<---
> From: Joel Fernandes <joelf@ti.com>
> Subject: [PATCH v6] 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.
> 
> 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.

The patch looks good to me. I made some modifications to commit message
- mostly for brevity.

    ARM: edma: dt: create unused channel list

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

    The above issue is fixed by reading the "dmas" property from
    the DT node if it exists and then clearing the bits in the
    unused channel list if the dma controller used by any device
    is EDMA.

    This is similar to approach taken in non-DT case.

    Also introduced is a minor clean up of a checkpatch error in
    old code.

Thanks,
Sekhar
diff mbox

Patch

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",