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| author | Benjamin Bigler <benjamin@bigler.one> | 2023-12-09 23:23:26 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2023-12-10 13:45:58 +0000 |
| commit | e9b220aeacf109684cce36a94fc24ed37be92b05 (patch) | |
| tree | 0c97189e1bb6ca61d63bc137f48f217fa9479bb5 /drivers | |
| parent | 7a733e060bd20edb63b1f27f0b29cf9b184e0e8b (diff) | |
| download | linux-stable-e9b220aeacf109684cce36a94fc24ed37be92b05.tar.gz linux-stable-e9b220aeacf109684cce36a94fc24ed37be92b05.tar.bz2 linux-stable-e9b220aeacf109684cce36a94fc24ed37be92b05.zip | |
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 <linux@bigler.io>
Signed-off-by: Benjamin Bigler <benjamin@bigler.one>
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 <broonie@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/spi/spi-imx.c | 15 |
1 files 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 */ |