In mcp251xfd_register_get_dev_id() the device ID register is read with handcrafted SPI transfers. As all registers, this register is in little endian. Further it is not naturally aligned in struct mcp251xfd_map_buf_nocrc::data. However after the transfer the register content is converted from big endian to CPU endianness not taking care of being unaligned. Fix the conversion by converting from little endian to CPU endianness taking the unaligned source into account. Side note: So far the register content is 0x0 on all mcp251xfd compatible chips, and is only used for an informative printk. Link: https://lore.kernel.org/all/20220627092859.809042-1-mkl@xxxxxxxxxxxxxx Fixes: 55e5b97f003e ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN") Reviewed-by: Rasmus Villemoes <rasmus.villemoes@xxxxxxxxx> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 3160881e89d9..9b47b07162fe 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -12,6 +12,7 @@ // Copyright (c) 2019 Martin Sperl <kernel@xxxxxxxxxxxxxxxx> // +#include <asm/unaligned.h> #include <linux/bitfield.h> #include <linux/clk.h> #include <linux/device.h> @@ -1787,7 +1788,7 @@ mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id, if (err) goto out_kfree_buf_tx; - *dev_id = be32_to_cpup((__be32 *)buf_rx->data); + *dev_id = get_unaligned_le32(buf_rx->data); *effective_speed_hz_slow = xfer[0].effective_speed_hz; *effective_speed_hz_fast = xfer[1].effective_speed_hz; -- 2.35.1
