From e9b220aeacf109684cce36a94fc24ed37be92b05 Mon Sep 17 00:00:00 2001 From: Benjamin Bigler Date: Sat, 9 Dec 2023 23:23:26 +0100 Subject: [PATCH] spi: spi-imx: correctly configure burst length when using dma If DMA is used, burst length should be set to the bus width of the DMA. Otherwise, the SPI hardware will transmit/receive one word per DMA request. Since this issue affects both transmission and reception, it cannot be detected with a loopback test. Replace magic numbers 512 and 0xfff with MX51_ECSPI_CTRL_MAX_BURST. Reported-by Stefan Bigler Signed-off-by: Benjamin Bigler Fixes: 15a6af94a277 ("spi: Increase imx51 ecspi burst length based on transfer length") Link: https://lore.kernel.org/r/8a415902c751cdbb4b20ce76569216ed@mail.infomaniak.com Link: https://lore.kernel.org/r/20231209222338.5564-1-benjamin@bigler.one Signed-off-by: Mark Brown --- drivers/spi/spi-imx.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 498e35c8db2c..272bc871a848 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -659,11 +659,18 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx, ctrl |= (spi_imx->target_burst * 8 - 1) << MX51_ECSPI_CTRL_BL_OFFSET; else { - if (spi_imx->count >= 512) - ctrl |= 0xFFF << MX51_ECSPI_CTRL_BL_OFFSET; - else - ctrl |= (spi_imx->count * spi_imx->bits_per_word - 1) + if (spi_imx->usedma) { + ctrl |= (spi_imx->bits_per_word * + spi_imx_bytes_per_word(spi_imx->bits_per_word) - 1) << MX51_ECSPI_CTRL_BL_OFFSET; + } else { + if (spi_imx->count >= MX51_ECSPI_CTRL_MAX_BURST) + ctrl |= (MX51_ECSPI_CTRL_MAX_BURST - 1) + << MX51_ECSPI_CTRL_BL_OFFSET; + else + ctrl |= (spi_imx->count * spi_imx->bits_per_word - 1) + << MX51_ECSPI_CTRL_BL_OFFSET; + } } /* set clock speed */