In Classical CAN there are RTR frames. RTR frames have the RTR bit set, may have a dlc != 0, but contain no data. This patch changes the RX-path to no copy any data for RTR frames, so that the data field in the CAN frame stays 0x0. Link: https://lore.kernel.org/r/20210114153448.1506901-4-mkl@xxxxxxxxxxxxxx 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 aa992e71d787..92816be4f3d4 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -1474,7 +1474,8 @@ mcp251xfd_hw_rx_obj_to_skb(const struct mcp251xfd_priv *priv, hw_rx_obj->flags)); } - memcpy(cfd->data, hw_rx_obj->data, cfd->len); + if (!(hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_RTR)) + memcpy(cfd->data, hw_rx_obj->data, cfd->len); } static int -- 2.29.2