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Message-ID: <a1cd6719-a743-fc96-e0e7-364a52b62952@acm.org>
Date:   Fri, 14 Oct 2022 11:37:36 -0700
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Subject: Re: [PATCH v2 1/2] scsi: ufs: core: Remove unnecessary if statement
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To:     Bean Huo <beanhuo@iokpp.de>, alim.akhtar@samsung.com,
        avri.altman@wdc.com, asutoshd@codeaurora.org, jejb@linux.ibm.com,
        martin.petersen@oracle.com, stanley.chu@mediatek.com,
        beanhuo@micron.com, tomas.winkler@intel.com, cang@codeaurora.org,
        daejun7.park@samsung.com
Cc:     linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20221010092937.520013-1-beanhuo@iokpp.de>
 <20221010092937.520013-2-beanhuo@iokpp.de>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20221010092937.520013-2-beanhuo@iokpp.de>
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On 10/10/22 02:29, Bean Huo wrote:
> From: Bean Huo <beanhuo@micron.com>
> 
> LUs with WB potential support are properly checked in ufshcd_wb_probe()
> before calling ufshcd_read_unit_desc_param(), so remove this unnecessary
> if-checkup in ufs_is_valid_unit_desc_lun() to match its function definition.
> 
> Signed-off-by: Bean Huo <beanhuo@micron.com>
> ---
>   drivers/ufs/core/ufshcd-priv.h | 3 ---
>   1 file changed, 3 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
> index f68ca33f6ac7..2457b005101a 100644
> --- a/drivers/ufs/core/ufshcd-priv.h
> +++ b/drivers/ufs/core/ufshcd-priv.h
> @@ -300,9 +300,6 @@ static inline bool ufs_is_valid_unit_desc_lun(struct ufs_dev_info *dev_info,
>   		pr_err("Max General LU supported by UFS isn't initialized\n");
>   		return false;
>   	}
> -	/* WB is available only for the logical unit from 0 to 7 */
> -	if (param_offset == UNIT_DESC_PARAM_WB_BUF_ALLOC_UNITS)
> -		return lun < UFS_UPIU_MAX_WB_LUN_ID;
>   	return lun == UFS_UPIU_RPMB_WLUN || (lun < dev_info->max_lu_supported);
>   }

Hi Bean,

I think the above patch reintroduces the stack overflow issue fixed by
commit a2fca52ee640 ("scsi: ufs: WB is only available on LUN #0 to #7").

How about reverting commit a2fca52ee640 and fixing the stack overflow
issue in another way than by modifying ufs_is_valid_unit_desc_lun()?

Thanks,

Bart.