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Message-ID: <06e0ae57-f567-4b90-ad68-4ae73909c29e@acm.org>
Date: Mon, 22 Jan 2024 12:36:30 -0800
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Subject: Re: [PATCH v1] scsi: ufs: core: Remove the ufshcd_release in
 ufshcd_err_handling_prepare
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To: SEO HOYOUNG <hy50.seo@samsung.com>, linux-scsi@vger.kernel.org,
 linux-kernel@vger.kernel.org, alim.akhtar@samsung.com, avri.altman@wdc.com,
 jejb@linux.ibm.com, martin.petersen@oracle.com, beanhuo@micron.com,
 kwangwon.min@samsung.com, kwmad.kim@samsung.com, sh425.lee@samsung.com,
 sc.suh@samsung.com, quic_nguyenb@quicinc.com, cpgs@samsung.com,
 grant.jung@samsung.com, junwoo80.lee@samsung.com
References: <CGME20240122083204epcas2p26a1bca522e201972ca072e0b24d23a52@epcas2p2.samsung.com>
 <20240122083324.11797-1-hy50.seo@samsung.com>
From: Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20240122083324.11797-1-hy50.seo@samsung.com>
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On 1/22/24 00:33, SEO HOYOUNG wrote:
> If err_handler is performed in the suspend/resume situation, ufs_release
> can be called twice and active_reqs valid can be negative.
> This is because ufshcd_errhandling_prepare() and
> ufshcd_err_handling_unprepare() repeatedly release calls.
> Eventually, active_reqs have a value different from the intention.
> To prevent this, release duplication processing was removed.
> 
> Signed-off-by: SEO HOYOUNG <hy50.seo@samsung.com>
> ---
>   drivers/ufs/core/ufshcd.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 7c59d7a02243..423e83074a20 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -6351,7 +6351,6 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
>   		ufshcd_hold(hba);
>   		if (!ufshcd_is_clkgating_allowed(hba))
>   			ufshcd_setup_clocks(hba, true);
> -		ufshcd_release(hba);
>   		pm_op = hba->is_sys_suspended ? UFS_SYSTEM_PM : UFS_RUNTIME_PM;
>   		ufshcd_vops_resume(hba, pm_op);
>   	} else {

I think that the above ufshcd_release() call pairs with the ufshcd_hold()
call three lines above it and hence that removing that call would be
wrong.

Thanks,

Bart.