Re: [PATCH v2] scsi: ufs: Disable WriteBooster capability in non-supported UFS device

[Asutosh Das (asd)]

On 6/24/2020 12:41 AM, Stanley Chu wrote:
> If UFS device is not qualified to enter the detection of WriteBooster
> probing by disallowed UFS version or device quirks, then WriteBooster
> capability in host shall be disabled to prevent any WriteBooster
> operations in the future.
>
> Fixes: 3d17b9b5ab11 ("scsi: ufs: Add write booster feature support")
> Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> ---
>   drivers/scsi/ufs/ufshcd.c | 35 +++++++++++++++++++----------------
>   1 file changed, 19 insertions(+), 16 deletions(-)
Reviewed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>


> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index f173ad1bd79f..c62bd47beeaa 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -6847,21 +6847,31 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
>   
>   static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
>   {
> +	struct ufs_dev_info *dev_info = &hba->dev_info;
>   	u8 lun;
>   	u32 d_lu_wb_buf_alloc;
>   
>   	if (!ufshcd_is_wb_allowed(hba))
>   		return;
> +	/*
> +	 * Probe WB only for UFS-2.2 and UFS-3.1 (and later) devices or
> +	 * UFS devices with quirk UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES
> +	 * enabled
> +	 */
> +	if (!(dev_info->wspecversion >= 0x310 ||
> +	      dev_info->wspecversion == 0x220 ||
> +	     (hba->dev_quirks & UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES)))
> +		goto wb_disabled;
>   
>   	if (hba->desc_size[QUERY_DESC_IDN_DEVICE] <
>   	    DEVICE_DESC_PARAM_EXT_UFS_FEATURE_SUP + 4)
>   		goto wb_disabled;
>   
> -	hba->dev_info.d_ext_ufs_feature_sup =
> +	dev_info->d_ext_ufs_feature_sup =
>   		get_unaligned_be32(desc_buf +
>   				   DEVICE_DESC_PARAM_EXT_UFS_FEATURE_SUP);
>   
> -	if (!(hba->dev_info.d_ext_ufs_feature_sup & UFS_DEV_WRITE_BOOSTER_SUP))
> +	if (!(dev_info->d_ext_ufs_feature_sup & UFS_DEV_WRITE_BOOSTER_SUP))
>   		goto wb_disabled;
>   
>   	/*
> @@ -6870,17 +6880,17 @@ static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
>   	 * a max of 1 lun would have wb buffer configured.
>   	 * Now only shared buffer mode is supported.
>   	 */
> -	hba->dev_info.b_wb_buffer_type =
> +	dev_info->b_wb_buffer_type =
>   		desc_buf[DEVICE_DESC_PARAM_WB_TYPE];
>   
> -	hba->dev_info.b_presrv_uspc_en =
> +	dev_info->b_presrv_uspc_en =
>   		desc_buf[DEVICE_DESC_PARAM_WB_PRESRV_USRSPC_EN];
>   
> -	if (hba->dev_info.b_wb_buffer_type == WB_BUF_MODE_SHARED) {
> -		hba->dev_info.d_wb_alloc_units =
> +	if (dev_info->b_wb_buffer_type == WB_BUF_MODE_SHARED) {
> +		dev_info->d_wb_alloc_units =
>   		get_unaligned_be32(desc_buf +
>   				   DEVICE_DESC_PARAM_WB_SHARED_ALLOC_UNITS);
> -		if (!hba->dev_info.d_wb_alloc_units)
> +		if (!dev_info->d_wb_alloc_units)
>   			goto wb_disabled;
>   	} else {
>   		for (lun = 0; lun < UFS_UPIU_MAX_WB_LUN_ID; lun++) {
> @@ -6891,7 +6901,7 @@ static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
>   					(u8 *)&d_lu_wb_buf_alloc,
>   					sizeof(d_lu_wb_buf_alloc));
>   			if (d_lu_wb_buf_alloc) {
> -				hba->dev_info.wb_dedicated_lu = lun;
> +				dev_info->wb_dedicated_lu = lun;
>   				break;
>   			}
>   		}
> @@ -6977,14 +6987,7 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>   
>   	ufs_fixup_device_setup(hba);
>   
> -	/*
> -	 * Probe WB only for UFS-3.1 devices or UFS devices with quirk
> -	 * UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES enabled
> -	 */
> -	if (dev_info->wspecversion >= 0x310 ||
> -	    dev_info->wspecversion == 0x220 ||
> -	    (hba->dev_quirks & UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES))
> -		ufshcd_wb_probe(hba, desc_buf);
> +	ufshcd_wb_probe(hba, desc_buf);
>   
>   	/*
>   	 * ufshcd_read_string_desc returns size of the string


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