Re: [PATCH v3 1/5] ufs: decode string descriptors as UTF-16 big-endian

[David Lechner <dlechner@baylibre.com>]

On 7/23/26 9:38 AM, Jorge Ramirez-Ortiz wrote:
> UFS string descriptors are UTF-16 big-endian (JESD220), but
> ufshcd_read_string_desc() fed the raw bytes to utf16_to_utf8(), which reads
> host-endian code units, leaving dev_desc->model blank. Byte-swap to host
> order before decoding, matching the kernel.
> 
> Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com>
> ---
>  drivers/ufs/ufs-uclass.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/ufs/ufs-uclass.c b/drivers/ufs/ufs-uclass.c
> index 6a51f337e47..8f120fbbee8 100644
> --- a/drivers/ufs/ufs-uclass.c
> +++ b/drivers/ufs/ufs-uclass.c
> @@ -1533,6 +1533,19 @@ static inline void ufshcd_remove_non_printable(uint8_t *val)
>  		*val = ' ';
>  }
>  
> +static inline void ufshcd_str_desc_to_cpu(u8 *desc, u32 size)
> +{
> +	u16 *p = (u16 *)&desc[QUERY_DESC_HDR_SIZE];
> +	u32 len = desc[QUERY_DESC_LENGTH_OFFSET];
> +	u32 i;
> +
> +	if (len > size)
> +		len = size;
> +
> +	for (i = QUERY_DESC_HDR_SIZE; i + 1 < len; i += 2, p++)
> +		*p = be16_to_cpu(*p);

I'm not a huge fan of modifying data in place like this. What do people
think about adding an endian parameter to utf16_to_utf8() instead?

> +}
> +
>  /**
>   * ufshcd_uic_pwr_ctrl - executes UIC commands (which affects the link power
>   * state) and waits for it to take effect.
> @@ -1765,6 +1778,8 @@ static int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index,
>  			goto out;
>  		}
>  
> +		ufshcd_str_desc_to_cpu(buf, size);
> +
>  		/*
>  		 * the descriptor contains string in UTF16 format
>  		 * we need to convert to utf-8 so it can be displayed