The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1c0e78a287e3493e22bde8553d02f3b89177eaf7 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde mkl@pengutronix.de Date: Mon, 20 Jun 2022 11:49:24 +0200 Subject: [PATCH] can: mcp251xfd: mcp251xfd_register_get_dev_id(): fix endianness conversion

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@pengutronix.de Fixes: 55e5b97f003e ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN") Reviewed-by: Rasmus Villemoes rasmus.villemoes@prevas.dk Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de

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@martin.sperl.org //

+#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;