[PATCH] can: mcp251xfd: mcp251xfd_register_get_dev_id(): fix endianness conversion

[PATCH] can: mcp251xfd: mcp251xfd_register_get_dev_id(): fix endianness conversion

[Marc Kleine-Budde]

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, too. However after the transfer the register content is
converted from big endian to CPU endianness.

Fix the conversion by converting from little endian to CPU endianness.

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")
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 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..d7f406dbe2ce 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 = le32_to_cpup((__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

Re: [PATCH] can: mcp251xfd: mcp251xfd_register_get_dev_id(): fix endianness conversion

[Rasmus Villemoes]

On 20/06/2022 16.49, Marc Kleine-Budde wrote:
> 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, too. However after the transfer the register content is
> converted from big endian to CPU endianness.
> 
> Fix the conversion by converting from little endian to CPU endianness.
> 
> Side note: So far the register content is 0x0 on all mcp251xfd
> compatible chips, and is only used for an informative printk.

Reviewed-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

Re: [PATCH] can: mcp251xfd: mcp251xfd_register_get_dev_id(): fix endianness conversion

[Manivannan Sadhasivam]

On Mon, Jun 20, 2022 at 04:49:54PM +0200, Marc Kleine-Budde wrote:
> 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, too. However after the transfer the register content is
> converted from big endian to CPU endianness.
> 
> Fix the conversion by converting from little endian to CPU endianness.
> 
> 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")
> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks,
Mani

> ---
>  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..d7f406dbe2ce 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 = le32_to_cpup((__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
> 
> 

-- 
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