Re: [PATCH] scsi: ufs: core: Handle sentinel value for dHIDAvailableSize

["Peter Wang (王信友)" <peter.wang@mediatek.com>]

On Fri, 2025-12-26 at 13:28 +0900, Keoseong Park wrote:
> JEDEC UFS spec defines 0xFFFFFFFF for dHIDAvailableSize as indicating
> no
> valid fragmented size information. Returning the raw value can
> mislead
> userspace. Return -ENODATA instead when the value is unavailable.
> 
> Signed-off-by: Keoseong Park <keosung.park@samsung.com>
> ---
>  drivers/ufs/core/ufs-sysfs.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-
> sysfs.c
> index b33f8656edb5..1017dd3ae5d3 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -1847,6 +1847,7 @@ static ssize_t defrag_trigger_store(struct
> device *dev,
> 
>  static DEVICE_ATTR_WO(defrag_trigger);
> 
> +#define UFS_HID_AVAILABLE_SIZE_INVALID 0xFFFFFFFFU
>  static ssize_t fragmented_size_show(struct device *dev,
>                 struct device_attribute *attr, char *buf)
>  {
> @@ -1859,6 +1860,9 @@ static ssize_t fragmented_size_show(struct
> device *dev,
>         if (ret)
>                 return ret;
> 
> +       if (value == UFS_HID_AVAILABLE_SIZE_INVALID)
> +               return -ENODATA;
> +
>         return sysfs_emit(buf, "%u\n", value);
>  }

Reviewed-by: Peter Wang <peter.wang@mediatek.com>