This is a note to let you know that I've just added the patch titled
dmaengine: xilinx_dma: program hardware supported buffer length
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-xilinx_dma-program-hardware-supported-buff.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 54d901bb07ec4a5895b36f24c68d14b59face162
Author: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxxxxx>
Date: Tue Nov 20 16:31:48 2018 +0100
dmaengine: xilinx_dma: program hardware supported buffer length
[ Upstream commit ae809690b46a71dc56cda5b3b8884c8c41a0df15 ]
AXI-DMA IP supports configurable (c_sg_length_width) buffer length
register width, hence read buffer length (xlnx,sg-length-width) DT
property and ensure that driver doesn't program buffer length
exceeding the supported limit. For VDMA and CDMA there is no change.
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: Andrea Merello <andrea.merello@xxxxxxxxx> [rebase, reword]
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Stable-dep-of: 596b53ccc36a ("dmaengine: xilinx_dma: call of_node_put() when breaking out of for_each_child_of_node()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index e4ea94b93400..6687cee26843 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -164,7 +164,9 @@
#define XILINX_DMA_REG_BTT 0x28
/* AXI DMA Specific Masks/Bit fields */
-#define XILINX_DMA_MAX_TRANS_LEN GENMASK(22, 0)
+#define XILINX_DMA_MAX_TRANS_LEN_MIN 8
+#define XILINX_DMA_MAX_TRANS_LEN_MAX 23
+#define XILINX_DMA_V2_MAX_TRANS_LEN_MAX 26
#define XILINX_DMA_CR_COALESCE_MAX GENMASK(23, 16)
#define XILINX_DMA_CR_CYCLIC_BD_EN_MASK BIT(4)
#define XILINX_DMA_CR_COALESCE_SHIFT 16
@@ -2634,7 +2636,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
struct xilinx_dma_device *xdev;
struct device_node *child, *np = pdev->dev.of_node;
struct resource *io;
- u32 num_frames, addr_width;
+ u32 num_frames, addr_width, len_width;
int i, err;
/* Allocate and initialize the DMA engine structure */
@@ -2666,10 +2668,24 @@ static int xilinx_dma_probe(struct platform_device *pdev)
/* Retrieve the DMA engine properties from the device tree */
xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
- xdev->max_buffer_len = XILINX_DMA_MAX_TRANS_LEN;
+ xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0);
- if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");
+ if (!of_property_read_u32(node, "xlnx,sg-length-width",
+ &len_width)) {
+ if (len_width < XILINX_DMA_MAX_TRANS_LEN_MIN ||
+ len_width > XILINX_DMA_V2_MAX_TRANS_LEN_MAX) {
+ dev_warn(xdev->dev,
+ "invalid xlnx,sg-length-width property value. Using default width\n");
+ } else {
+ if (len_width > XILINX_DMA_MAX_TRANS_LEN_MAX)
+ dev_warn(xdev->dev, "Please ensure that IP supports buffer length > 23 bits\n");
+ xdev->max_buffer_len =
+ GENMASK(len_width - 1, 0);
+ }
+ }
+ }
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
err = of_property_read_u32(node, "xlnx,num-fstores",
