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| author | CL Wang <cl634@andestech.com> | 2026-03-03 10:47:37 +0800 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2026-03-11 19:08:43 +0000 |
| commit | f879365c5bb210ed0d0b0aae1a0202d0c0b4b9d0 (patch) | |
| tree | ec0250a441ce37bd864a0b4e909b462585b4312f /drivers/spi | |
| parent | 743956bb9990214ff1dac66ef59e27221dc3c2d8 (diff) | |
| download | linux-next-f879365c5bb210ed0d0b0aae1a0202d0c0b4b9d0.tar.gz linux-next-f879365c5bb210ed0d0b0aae1a0202d0c0b4b9d0.zip | |
spi: atcspi200: Handle invalid buswidth and fix compiler warning
The kernel test robot reported a compile-time error regarding the
FIELD_PREP() value being too large for the TRANS_DUAL_QUAD field:
error: FIELD_PREP: value too large for the field
note: in expansion of macro 'TRANS_DUAL_QUAD'
tc |= TRANS_DUAL_QUAD(ffs(op->data.buswidth) - 1);
This occurs because TRANS_DUAL_QUAD is defined as a 2-bit field, and
GCC's static analysis cannot deduce that `ffs(op->data.buswidth) - 1`
will strictly fall within the 0~3 range. Although the SPI framework
guarantees that `op->data.buswidth` is valid at runtime (e.g., 1, 2,
4, 8), an explicit bounds check is necessary to satisfy the compiler.
To resolve the build warning, introduce a safe fallback mechanism.
If an unexpected buswidth is encountered, the driver will trigger
a WARN_ON_ONCE to leave a trace and fall back to width_code = 0
(standard 1-bit SPI mode). This approach guarantees predictable
hardware behavior.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602140738.P7ZozxzI-lkp@intel.com/
Suggested-by: Pei Xiao <xiaopei01@kylinos.cn>
Signed-off-by: CL Wang <cl634@andestech.com>
Link: https://patch.msgid.link/20260303024737.1791196-1-cl634@andestech.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-atcspi200.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/spi/spi-atcspi200.c b/drivers/spi/spi-atcspi200.c index fef6954d27e1..2665f31a49ce 100644 --- a/drivers/spi/spi-atcspi200.c +++ b/drivers/spi/spi-atcspi200.c @@ -195,7 +195,15 @@ static void atcspi_set_trans_ctl(struct atcspi_dev *spi, if (op->addr.buswidth > 1) tc |= TRANS_ADDR_FMT; if (op->data.nbytes) { - tc |= TRANS_DUAL_QUAD(ffs(op->data.buswidth) - 1); + unsigned int width_code; + + width_code = ffs(op->data.buswidth) - 1; + if (unlikely(width_code > 3)) { + WARN_ON_ONCE(1); + width_code = 0; + } + tc |= TRANS_DUAL_QUAD(width_code); + if (op->data.dir == SPI_MEM_DATA_IN) { if (op->dummy.nbytes) tc |= TRANS_MODE_DMY_READ | |