openwrt/target/linux/bcm27xx/patches-5.4/950-0924-bcm2835-dma-Advertise-the-full-DMA-range.patch

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From bf7baee1935c4d485083c3b3c439631ae4ac3c0f Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Wed, 22 Jul 2020 17:59:31 +0100
Subject: [PATCH] bcm2835-dma: Advertise the full DMA range
Unless the DMA mask is set wider than 32 bits, DMA mapping will use a
bounce buffer.
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
drivers/dma/bcm2835-dma.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -41,6 +41,7 @@
#define BCM2711_DMA_MEMCPY_CHAN 14
struct bcm2835_dma_cfg_data {
+ u64 dma_mask;
u32 chan_40bit_mask;
};
@@ -302,10 +303,12 @@ DEFINE_SPINLOCK(memcpy_lock);
static const struct bcm2835_dma_cfg_data bcm2835_dma_cfg = {
.chan_40bit_mask = 0,
+ .dma_mask = DMA_BIT_MASK(32),
};
static const struct bcm2835_dma_cfg_data bcm2711_dma_cfg = {
.chan_40bit_mask = BIT(11) | BIT(12) | BIT(13) | BIT(14),
+ .dma_mask = DMA_BIT_MASK(36),
};
static inline size_t bcm2835_dma_max_frame_length(struct bcm2835_chan *c)
@@ -1185,6 +1188,8 @@ static struct dma_chan *bcm2835_dma_xlat
static int bcm2835_dma_probe(struct platform_device *pdev)
{
+ const struct bcm2835_dma_cfg_data *cfg_data;
+ const struct of_device_id *of_id;
struct bcm2835_dmadev *od;
struct resource *res;
void __iomem *base;
@@ -1194,13 +1199,20 @@ static int bcm2835_dma_probe(struct plat
int irq_flags;
uint32_t chans_available;
char chan_name[BCM2835_DMA_CHAN_NAME_SIZE];
- const struct of_device_id *of_id;
int chan_count, chan_start, chan_end;
+ of_id = of_match_node(bcm2835_dma_of_match, pdev->dev.of_node);
+ if (!of_id) {
+ dev_err(&pdev->dev, "Failed to match compatible string\n");
+ return -EINVAL;
+ }
+
+ cfg_data = of_id->data;
+
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
- rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ rc = dma_set_mask_and_coherent(&pdev->dev, cfg_data->dma_mask);
if (rc) {
dev_err(&pdev->dev, "Unable to set DMA mask\n");
return rc;
@@ -1266,7 +1278,7 @@ static int bcm2835_dma_probe(struct plat
return -EINVAL;
}
- od->cfg_data = of_id->data;
+ od->cfg_data = cfg_data;
/* Request DMA channel mask from device tree */
if (of_property_read_u32(pdev->dev.of_node,