Unverified Commit 71050521 authored by Cheng Ming Lin's avatar Cheng Ming Lin Committed by Mark Brown
Browse files

spi: Add check for 8-bit transfer with 8 IO mode support 



The current SPI framework does not verify if the SPI device supports
8 IO mode when doing an 8-bit transfer. This patch adds a check to
ensure that if the transfer tx_nbits or rx_nbits is 8, the SPI mode must
support 8 IO. If not, an error is returned, preventing undefined behavior.

Fixes: d6a711a8 ("spi: Fix OCTAL mode support")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarCheng Ming Lin <chengminglin@mxic.com.tw>
Link: https://patch.msgid.link/20250714031023.504752-1-linchengming884@gmail.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent d7b8f8e2

drivers/spi/spi.c

+10 −4
Original line number Diff line number Diff line
@@ -4138,10 +4138,13 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) 
				xfer->tx_nbits != SPI_NBITS_OCTAL)

				return -EINVAL;

			if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&

				!(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))

				!(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL)))

				return -EINVAL;

			if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&

				!(spi->mode & SPI_TX_QUAD))

				!(spi->mode & (SPI_TX_QUAD | SPI_TX_OCTAL)))

				return -EINVAL;

			if ((xfer->tx_nbits == SPI_NBITS_OCTAL) &&

				!(spi->mode & SPI_TX_OCTAL))

				return -EINVAL;

		}

		/* Check transfer rx_nbits */
@@ -4154,10 +4157,13 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) 
				xfer->rx_nbits != SPI_NBITS_OCTAL)

				return -EINVAL;

			if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&

				!(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))

				!(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))

				return -EINVAL;

			if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&

				!(spi->mode & SPI_RX_QUAD))

				!(spi->mode & (SPI_RX_QUAD | SPI_RX_OCTAL)))

				return -EINVAL;

			if ((xfer->rx_nbits == SPI_NBITS_OCTAL) &&

				!(spi->mode & SPI_RX_OCTAL))

				return -EINVAL;

		}