The current code uses a BIT() operation which is wrong. Comparing the upstream code with the Lantiq UGW kernel we see that burst length should be set to 4 bytes. Signed-off-by: John Crispin <blogic@xxxxxxxxxxx> --- Changes in V2: * dont use BIT() arch/mips/lantiq/xway/dma.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/mips/lantiq/xway/dma.c b/arch/mips/lantiq/xway/dma.c index 08f7ebd..c99b129 100644 --- a/arch/mips/lantiq/xway/dma.c +++ b/arch/mips/lantiq/xway/dma.c @@ -48,7 +48,8 @@ #define DMA_IRQ_ACK 0x7e /* IRQ status register */ #define DMA_POLL BIT(31) /* turn on channel polling */ #define DMA_CLK_DIV4 BIT(6) /* polling clock divider */ -#define DMA_2W_BURST BIT(1) /* 2 word burst length */ +#define DMA_4W_BURST 2 /* 4 word burst length */ +#define DMA_2W_BURST 1 /* 2 word burst length */ #define DMA_MAX_CHANNEL 20 /* the soc has 20 channels */ #define DMA_ETOP_ENDIANNESS (0xf << 8) /* endianness swap etop channels */ #define DMA_WEIGHT (BIT(17) | BIT(16)) /* default channel wheight */ @@ -196,7 +197,8 @@ ltq_dma_init_port(int p) * Tell the DMA engine to swap the endianness of data frames and * drop packets if the channel arbitration fails. */ - ltq_dma_w32_mask(0, DMA_ETOP_ENDIANNESS | DMA_PDEN, + ltq_dma_w32_mask(0, (DMA_4W_BURST << 4) | (DMA_4W_BURST << 2) | + DMA_ETOP_ENDIANNESS | DMA_PDEN, LTQ_DMA_PCTRL); break; -- 1.7.10.4
