RE: [PATCH v7 RESEND 07/13] spi: imx: fix ERR009165
From: Robin Gong <hidden>
Date: 2020-05-13 09:05:41
Also in:
dmaengine, linux-arm-kernel, linux-spi, lkml
On 2020/05/13 Sascha Hauer [off-list ref] wrote:d
quoted hunk ↗ jump to hunk
quoted
drivers/spi/spi-imx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c indexf4f28a4..70df8e6 100644--- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c@@ -585,8 +585,8 @@ static int mx51_ecspi_prepare_transfer(structspi_imx_data *spi_imx,quoted
ctrl |= mx51_ecspi_clkdiv(spi_imx, t->speed_hz, &clk); spi_imx->spi_bus_clk = clk; - if (spi_imx->usedma) - ctrl |= MX51_ECSPI_CTRL_SMC; + /* ERR009165: work in XHC mode as PIO */ + ctrl &= ~MX51_ECSPI_CTRL_SMC; writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);@@ -617,7 +617,7 @@ static void mx51_setup_wml(struct spi_imx_data*spi_imx)quoted
* 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(0) | 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);@@ -1171,7quoted
+1171,11 @@ 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;In the next patch this is changed again to: + if (spi_imx->devtype_data->tx_glitch_fixed) + tx.dst_maxburst = spi_imx->wml; + else + tx.dst_maxburst = spi_imx->devtype_data->fifo_size; So with tx_glitch_fixed we end up with tx.dst_maxburst being the same as two patches before which is rather confusing. Better introduce tx_glitch_fixed in this patch, or maybe even merge this patch and the next one.
Sorry confused you, I should repleace 'tx_wml=0' in the above comments with ' TX_THRESHOLD=0', which means tx transfer dma have to wait all the tx data in tx fifo transferred with ERR009165 rather than generically 'tx_wml' (for example --half fifo size used as TX_THRESHOLD). Obviously TX_THRESHOLD=0 would down performance, so enlarge dst_maxburst to fifo size as PIO with ERR009165. After ERR009165 fixed at HW level. TX_THRESHOLD could be used as common 'spi_imx->wml' so change it back. Will add more detail information in v8.