spi: virtio: Use the per-transfer bits per word

virtio_spi_transfer_one() puts spi->bits_per_word into the request
header, so a transfer that sets its own word size reaches the backend
with the device default instead. The SPI core has already copied that
default into xfer->bits_per_word when the transfer leaves it at zero,
the same way it does for xfer->speed_hz, which this function already
uses.

Per-transfer word sizes are ordinary SPI usage. mipi_dbi, for one, sends
a 9-bit command and reads the reply as 8-bit data in the same message.
With a 16-bit device default, a one-byte transfer asking for 8 bits goes
out as a partial 16-bit word, which the backend may reject.

Fixes: f98cabe3f6cf ("SPI: Add virtio SPI driver")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Hao-Qun Huang <alvinhuang0603@gmail.com>
Link: https://patch.msgid.link/20260913032049.11209.alvinhuang0603@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

0 files changed, 0 insertions, 0 deletions