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: Olivier Dautricourt <olivier.dautricourt@xxxxxxxxxx> --- drivers/dma/altera-msgdma.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/drivers/dma/altera-msgdma.c b/drivers/dma/altera-msgdma.c index 0fe0676f8e1d..5a2c7573b692 100644 --- a/drivers/dma/altera-msgdma.c +++ b/drivers/dma/altera-msgdma.c @@ -691,10 +691,14 @@ static void msgdma_tasklet(struct tasklet_struct *t) spin_lock_irqsave(&mdev->lock, flags); - /* 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); + 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; -- 2.31.0.rc2
