diff options
| author | Carlos Song <carlos.song@nxp.com> | 2025-11-17 11:03:55 +0800 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2025-11-21 14:23:45 +0000 |
| commit | 9f0c21bac5a8089e74b21d007e26fb4594b10d73 (patch) | |
| tree | 0d1eea37deaaf16349d76d02c189d719fd27eead | |
| parent | 295fe8406a357bc0abb901a21d1a554fd4dd1d05 (diff) | |
spi: spi-fsl-lpspi: fix watermark truncation caused by type cast
't->len' is an unsigned integer, while 'watermark' and 'txfifosize' are
u8. Using min_t with typeof(watermark) forces both values to be cast to
u8, which truncates len when it exceeds 255. For example, len = 4096
becomes 0 after casting, resulting in an incorrect watermark value.
Use a wider type in min_t to avoid truncation and ensure the correct
minimum value is applied.
Fixes: a750050349ea ("spi: spi-fsl-lpspi: use min_t() to improve code")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Link: https://patch.msgid.link/20251117030355.1359081-1-carlos.song@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
| -rw-r--r-- | drivers/spi/spi-fsl-lpspi.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index 8da66e101386..065456aba2ae 100644 --- a/drivers/spi/spi-fsl-lpspi.c +++ b/drivers/spi/spi-fsl-lpspi.c @@ -486,7 +486,13 @@ static int fsl_lpspi_setup_transfer(struct spi_controller *controller, fsl_lpspi->tx = fsl_lpspi_buf_tx_u32; } - fsl_lpspi->watermark = min_t(typeof(fsl_lpspi->watermark), + /* + * t->len is 'unsigned' and txfifosize and watermrk is 'u8', force + * type cast is inevitable. When len > 255, len will be truncated in min_t(), + * it caused wrong watermark set. 'unsigned int' is as the designated type + * for min_t() to avoid truncation. + */ + fsl_lpspi->watermark = min_t(unsigned int, fsl_lpspi->txfifosize, t->len); |