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.
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>
---
Hello,
just noticed, that buf_rx->data is not naturally aligned if
interpreting it as a 32 bit value.
regards,
Marc
changes since v1:
- use get_unaligned_le32() instead of be32_to_cpup()
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 3160881e89d9..aa17e437585a 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -1787,7 +1787,7 @@ 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
