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From: "Kiwoong Kim" <kwmad.kim@samsung.com>
To: "'Bart Van Assche'" <bvanassche@acm.org>,
	<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>, <cang@codeaurora.org>,
	<adrian.hunter@intel.com>, <sc.suh@samsung.com>,
	<hy50.seo@samsung.com>, <sh425.lee@samsung.com>,
	<bhoon95.kim@samsung.com>, <vkumar.1997@samsung.com>
Subject: RE: [PATCH v1] scsi: ufs: remove clk_scaling_lock when clkscaling isn't supported.
Date: Tue, 15 Feb 2022 15:03:25 +0900	[thread overview]
Message-ID: <007e01d82231$be8be250$3ba3a6f0$@samsung.com> (raw)
In-Reply-To: <62a5170b-48c0-a372-5392-08f5112d7a06@acm.org>

> > -	down_read(&hba->clk_scaling_lock);
> > +	if (ufshcd_is_clkscaling_supported(hba))
> > +		down_read(&hba->clk_scaling_lock);
> >
> >   	lrbp = &hba->lrb[tag];
> >   	WARN_ON(lrbp->cmd);
> 
> I don't like this patch at all. This patch makes testing the UFS driver
> more complicated without having any clear benefit. Additionally, adding
> if-statements in front of locking makes static source code analysis harder
> and is an anti-pattern. Please don't do this.
> 
> Bart. 

The benefit that I think is not blocking dev cmd during submitting a scsi cmd.
Rather, I don't understand why this lock is required if a SoC doesn't support clk scaling.

The period of ringing doorbells has been already protected by spin lock.

Thanks.
Kiwoong Kim


  reply	other threads:[~2022-02-15  6:03 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20220205074128epcas2p40901c37a7328e825d8697f8d3269edba@epcas2p4.samsung.com>
2022-02-05  7:39 ` [PATCH v1] scsi: ufs: remove clk_scaling_lock when clkscaling isn't supported Kiwoong Kim
2022-02-06  8:20   ` Avri Altman
2022-02-11  2:15     ` Kiwoong Kim
2022-02-11 12:15       ` Adrian Hunter
2022-02-12  4:44         ` Kiwoong Kim
2022-02-14 14:31           ` Adrian Hunter
2022-02-15 11:00           ` Bean Huo
2022-02-15 17:09             ` Bart Van Assche
2022-02-17  8:12             ` Kiwoong Kim
2022-02-11 12:19       ` Avri Altman
2022-02-14 19:29   ` Bart Van Assche
2022-02-15  6:03     ` Kiwoong Kim [this message]
2022-02-15 17:15       ` Bart Van Assche
2022-02-17  8:15         ` Kiwoong Kim

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