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Subject: Re: [PATCH v4 03/10] scsi: ufs: Update the return value of supplier
 pm ops
To:     Can Guo <cang@codeaurora.org>, asutoshd@codeaurora.org,
        nguyenb@codeaurora.org, hongwus@codeaurora.org,
        ziqichen@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        open list <linux-kernel@vger.kernel.org>
References: <1624433711-9339-1-git-send-email-cang@codeaurora.org>
 <1624433711-9339-4-git-send-email-cang@codeaurora.org>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <59b0c04a-298a-4eae-7938-8170835c00b7@acm.org>
Date:   Wed, 23 Jun 2021 14:08:22 -0700
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On 6/23/21 12:35 AM, Can Guo wrote:
> rpm_get_suppliers() is returning an error only if the error is negative.
> However, ufshcd_wl_resume() may return a positive error code, e.g., when
> hibern8 or SSU cmd fails. Make the positive return value a negative error
> code so that consumers are aware of any resume failure from their supplier.
> Make the same change to ufshcd_wl_suspend() just to keep symmetry.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufshcd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index abe5f2d..ee70522 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -8922,7 +8922,7 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		ufshcd_release(hba);
>  	}
>  	hba->wlu_pm_op_in_progress = false;
> -	return ret;
> +	return ret <= 0 ? ret : -EINVAL;
>  }
>  
>  static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> @@ -9009,7 +9009,7 @@ static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	hba->clk_gating.is_suspended = false;
>  	ufshcd_release(hba);
>  	hba->wlu_pm_op_in_progress = false;
> -	return ret;
> +	return ret <= 0 ? ret : -EINVAL;
>  }

I think the above patch shows that indicating failure by either
returning a positive or a negative value is a booby trap. Please modify
ufshcd_send_request_sense() and ufshcd_set_dev_pwr_mode() such that
these return a value that is either zero or negative. Are there any
other functions than that need to be modified?

Thanks,

Bart.