Commit 80abf888 authored by Addy Ke's avatar Addy Ke Committed by Vinod Koul
Browse files

spi: rockchip: modify DMA max burst to 1 



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: default avatarAddy ke <addy.ke@rock-chips.com>
Fixes: 64e36824 ("spi/rockchip: add driver for Rockchip...")
Signed-off-by: default avatarShawn 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: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarCaesar Wang <wxt@rock-chips.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 86a8ce7d

drivers/spi/spi-rockchip.c

+10 −2
Original line number Diff line number Diff line
@@ -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;

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