On Tue, Mar 10, 2020 at 07:31:55PM +0800, Robin Gong wrote: > Change to XCH mode even in dma mode, please refer to the below > errata: > https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf > > Signed-off-by: Robin Gong <yibin.gong@xxxxxxx> > Acked-by: Mark Brown <broonie@xxxxxxxxxx> > --- > drivers/spi/spi-imx.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c > index f4f28a4..842a86e 100644 > --- a/drivers/spi/spi-imx.c > +++ b/drivers/spi/spi-imx.c > @@ -585,8 +585,9 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx, > ctrl |= mx51_ecspi_clkdiv(spi_imx, t->speed_hz, &clk); > spi_imx->spi_bus_clk = clk; > > + /* ERR009165: work in XHC mode as PIO */ > if (spi_imx->usedma) > - ctrl |= MX51_ECSPI_CTRL_SMC; > + ctrl &= ~MX51_ECSPI_CTRL_SMC; 'ctrl' was read from the hardware. In the dma case it was set explicitly, but it was never cleared for a PIO transfer. This looked wrong before this patch. Now with this patch it looks even more wrong: We clear a bit that has never been set and we only do this for DMA, when for the PIO case it definitly must be cleared. Drop the if clause. > > writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL); > > @@ -612,12 +613,14 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx, > > static void mx51_setup_wml(struct spi_imx_data *spi_imx) > { > + u32 tx_wml = 0; > + > /* > * Configure the DMA register: setup the watermark > * and enable DMA request. > */ > writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml - 1) | > - MX51_ECSPI_DMA_TX_WML(spi_imx->wml) | > + MX51_ECSPI_DMA_TX_WML(tx_wml) | tx_wml is never assigned any other value than 0. Drop the variable. > MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) | > MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN | > MX51_ECSPI_DMA_RXTDEN, spi_imx->base + MX51_ECSPI_DMA); > @@ -1171,7 +1174,11 @@ static int spi_imx_dma_configure(struct spi_master *master) > tx.direction = DMA_MEM_TO_DEV; > tx.dst_addr = spi_imx->base_phys + MXC_CSPITXDATA; > tx.dst_addr_width = buswidth; > - tx.dst_maxburst = spi_imx->wml; > + /* > + * For ERR009165 with tx_wml = 0 could enlarge burst size to fifo size > + * to speed up fifo filling as possible. > + */ > + tx.dst_maxburst = spi_imx->devtype_data->fifo_size; > ret = dmaengine_slave_config(master->dma_tx, &tx); > if (ret) { > dev_err(spi_imx->dev, "TX dma configuration failed with %d\n", ret); > @@ -1265,10 +1272,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, > { > int ret; > > - /* use pio mode for i.mx6dl chip TKT238285 */ > - if (of_machine_is_compatible("fsl,imx6dl")) > - return 0; So with this patch it becomes possible to do DMA on i.MX6dl, but it is mentioned nowhere. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
