From: Addy Ke addy.ke@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.ke@rock-chips.com Fixes: 64e36824b32b06 ("spi/rockchip: add driver for Rockchip...") Signed-off-by: Shawn Lin shawn.lin@rock-chips.com cc: Heiko Stuebner heiko@sntech.de cc: Olof Johansson olof@lixom.net cc: Doug Anderson dianders@chromium.org cc: Sonny Rao sonnyrao@chromium.org
Acked-by: Mark Brown broonie@kernel.org ---
Changes in v6: - remove quirks and get dma caps in order to limit burst
Changes in v5: None Changes in v4: None Changes in v3: None Changes in v2: None Changes in v1: None
drivers/spi/spi-rockchip.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 79a8bc4..aa9561f 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -199,6 +199,7 @@ struct rockchip_spi { struct sg_table rx_sg; struct rockchip_spi_dma_data dma_rx; struct rockchip_spi_dma_data dma_tx; + struct dma_slave_caps dma_caps; };
static inline void spi_enable_chip(struct rockchip_spi *rs, int enable) @@ -449,7 +450,10 @@ 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->dma_caps.max_burst > 4) + rxconf.src_maxburst = 4; + else + rxconf.src_maxburst = 1; dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
rxdesc = dmaengine_prep_slave_sg( @@ -466,7 +470,10 @@ 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->dma_caps.max_burst > 4) + txconf.dst_maxburst = 4; + else + txconf.dst_maxburst = 1; dmaengine_slave_config(rs->dma_tx.ch, &txconf);
txdesc = dmaengine_prep_slave_sg( @@ -730,6 +737,7 @@ static int rockchip_spi_probe(struct platform_device *pdev) }
if (rs->dma_tx.ch && rs->dma_rx.ch) { + dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps)); rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR); rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR); rs->dma_tx.direction = DMA_MEM_TO_DEV;