From: Addy Ke <addy...@rock-chips.com>
Generic dma controller on Rockchips' platform cannot support
DMAFLUSHP instruction which make dma to flush the req of non-aligned
or non-multiple of what we need. That will cause an unrecoverable
dma bus error. The saftest way is to set dma max burst to 1.
Signed-off-by: Addy ke <addy...@rock-chips.com>
Fixes: 64e36824b32b06 ("spi/rockchip: add driver for Rockchip...")
Signed-off-by: Shawn Lin <shawn....@rock-chips.com>
cc: Heiko Stuebner <he...@sntech.de>
cc: Olof Johansson <o...@lixom.net>
cc: Doug Anderson <diand...@chromium.org>
cc: Sonny Rao <sonny...@chromium.org>
---
Changes in v3: None
Changes in v2: None
Changes in v1: None
drivers/spi/spi-rockchip.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index 68e7efe..3748ca5 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -199,6 +199,8 @@ struct rockchip_spi {
struct sg_table rx_sg;
struct rockchip_spi_dma_data dma_rx;
struct rockchip_spi_dma_data dma_tx;
+ int quirk;
+#define ROCKCHIP_SPI_BORKEN_BURST_LEN (1<<0) /* broken burst len*/
};
static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
@@ -449,7 +451,10 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi
*rs)
rxconf.direction = rs->dma_rx.direction;
rxconf.src_addr = rs->dma_rx.addr;
rxconf.src_addr_width = rs->n_bytes;
- rxconf.src_maxburst = rs->n_bytes;
+ if (rs->quirk & ROCKCHIP_SPI_BORKEN_BURST_LEN)
+ rxconf.src_maxburst = 1;
+ else
+ rxconf.src_maxburst = rs->n_bytes;
dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
rxdesc = dmaengine_prep_slave_sg(
@@ -466,7 +471,10 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi
*rs)
txconf.direction = rs->dma_tx.direction;
txconf.dst_addr = rs->dma_tx.addr;
txconf.dst_addr_width = rs->n_bytes;
- txconf.dst_maxburst = rs->n_bytes;
+ if (rs->quirk & ROCKCHIP_SPI_BORKEN_BURST_LEN)
+ txconf.dst_maxburst = 1;
+ else
+ txconf.dst_maxburst = rs->n_bytes;
dmaengine_slave_config(rs->dma_tx.ch, &txconf);
txdesc = dmaengine_prep_slave_sg(
@@ -699,6 +707,10 @@ static int rockchip_spi_probe(struct platform_device *pdev)
goto err_get_fifo_len;
}
+ if (of_property_read_bool(pdev->dev.of_node,
+ "rockchip,spi-broken-burst-len"))
+ rs->quirk |= ROCKCHIP_SPI_BORKEN_BURST_LEN;
+
spin_lock_init(&rs->lock);
pm_runtime_set_active(&pdev->dev);
--
2.3.7
--
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