Commit af2eec75 authored by Olivier Dautricourt's avatar Olivier Dautricourt Committed by Vinod Koul
Browse files

dmaengine: altera-msgdma: make response port optional 

The response slave port can be disabled in some configuration [1] and
csr + MSGDMA_CSR_RESP_FILL_LEVEL will be 0 even if transfer has suceeded.
We have to only rely on the interrupts in that scenario.
This was tested on cyclone V with the controller resp port disabled.

[1] https://www.intel.com/content/www/us/en/programmable/documentation/sfo1400787952932.html
30.3.1.2
30.3.1.3
30.5.5

Fixes: https://forum.rocketboards.org/t/ip-msgdma-linux-driver/1919


Signed-off-by: default avatarOlivier Dautricourt <olivier.dautricourt@orolia.com>
Reviewed-by: default avatarStefan Roese <sr@denx.de>
Link: https://lore.kernel.org/r/8220756f2191ca08cb21702252d1f2d4f753a7f5.1623898678.git.olivier.dautricourt@orolia.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 4aece33c

drivers/dma/altera-msgdma.c

+26 −11
Original line number Diff line number Diff line
@@ -691,10 +691,14 @@ static void msgdma_tasklet(struct tasklet_struct *t) 


	spin_lock_irqsave(&mdev->lock, flags);



	if (mdev->resp) {

		/* Read number of responses that are available */

		count = ioread32(mdev->csr + MSGDMA_CSR_RESP_FILL_LEVEL);

		dev_dbg(mdev->dev, "%s (%d): response count=%d\n",

			__func__, __LINE__, count);

	} else {

		count = 1;

	}



	while (count--) {

		/*
@@ -703,8 +707,12 @@ static void msgdma_tasklet(struct tasklet_struct *t) 
		 * have any real values, like transferred bytes or error

		 * bits. So we need to just drop these values.

		 */

		size = ioread32(mdev->resp + MSGDMA_RESP_BYTES_TRANSFERRED);

		status = ioread32(mdev->resp + MSGDMA_RESP_STATUS);

		if (mdev->resp) {

			size = ioread32(mdev->resp +

					MSGDMA_RESP_BYTES_TRANSFERRED);

			status = ioread32(mdev->resp +

					MSGDMA_RESP_STATUS);

		}



		msgdma_complete_descriptor(mdev);

		msgdma_chan_desc_cleanup(mdev);
@@ -757,14 +765,21 @@ static void msgdma_dev_remove(struct msgdma_device *mdev) 
}



static int request_and_map(struct platform_device *pdev, const char *name,

			   struct resource **res, void __iomem **ptr)

			   struct resource **res, void __iomem **ptr,

			   bool optional)

{

	struct resource *region;

	struct device *device = &pdev->dev;



	*res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);

	if (*res == NULL) {

		dev_err(device, "resource %s not defined\n", name);

		if (optional) {

			*ptr = NULL;

			dev_info(device, "optional resource %s not defined\n",

				 name);

			return 0;

		}

		dev_err(device, "mandatory resource %s not defined\n", name);

		return -ENODEV;

	}
@@ -805,17 +820,17 @@ static int msgdma_probe(struct platform_device *pdev) 
	mdev->dev = &pdev->dev;



	/* Map CSR space */

	ret = request_and_map(pdev, "csr", &dma_res, &mdev->csr);

	ret = request_and_map(pdev, "csr", &dma_res, &mdev->csr, false);

	if (ret)

		return ret;



	/* Map (extended) descriptor space */

	ret = request_and_map(pdev, "desc", &dma_res, &mdev->desc);

	ret = request_and_map(pdev, "desc", &dma_res, &mdev->desc, false);

	if (ret)

		return ret;



	/* Map response space */

	ret = request_and_map(pdev, "resp", &dma_res, &mdev->resp);

	ret = request_and_map(pdev, "resp", &dma_res, &mdev->resp, true);

	if (ret)

		return ret;