From: "Chew, Chiau Ee" <[email protected]> This is to fix the SPI DMA transfer failure for speed less than 1M. If using current DMA burst size setting (16), the Rx data bytes are invalid due to each data byte is multiplied according to the burst size setting.
Let's said supposedly we shall receive the following 18 bytes of data: 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 Instead, the data bytes received consist of "16 bytes of '01' + 2 bytes of '02'" : 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 02 02 Signed-off-by: Chew, Chiau Ee <[email protected]> Acked-by: Mika Westerberg <[email protected]> Signed-off-by: Mark Brown <[email protected]> (cherry picked from commit 01d7aafb3fbaafe2403780ef9ed497b3289ab1b9) Signed-off-by: Chang Rebecca Swee Fun <[email protected]> --- drivers/spi/spi-pxa2xx-dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-pxa2xx-dma.c b/drivers/spi/spi-pxa2xx-dma.c index 07a4625..6fc2bc1 100644 --- a/drivers/spi/spi-pxa2xx-dma.c +++ b/drivers/spi/spi-pxa2xx-dma.c @@ -369,7 +369,7 @@ int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip, * otherwise we use the default. Also we use the default FIFO * thresholds for now. */ - *burst_code = chip_info ? chip_info->dma_burst_size : 16; + *burst_code = chip_info ? chip_info->dma_burst_size : 1; *threshold = SSCR1_RxTresh(RX_THRESH_DFLT) | SSCR1_TxTresh(TX_THRESH_DFLT); -- 1.9.1 -- _______________________________________________ linux-yocto mailing list [email protected] https://lists.yoctoproject.org/listinfo/linux-yocto
