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Message-ID: <eee9f5b0a1f9e52a1ea569403cc183fb48dd77a9.camel@gmail.com>
Date: Tue, 22 Dec 2020 22:08:56 +0100
From: Bean Huo <huobean@...il.com>
To: Stanley Chu <stanley.chu@...iatek.com>
Cc: alim.akhtar@...sung.com, avri.altman@....com,
asutoshd@...eaurora.org, jejb@...ux.ibm.com,
martin.petersen@...cle.com, beanhuo@...ron.com, bvanassche@....org,
tomas.winkler@...el.com, cang@...eaurora.org,
linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 1/7] scsi: ufs: Add "wb_on" sysfs node to control WB
on/off
On Tue, 2020-12-22 at 21:50 +0100, Bean Huo wrote:
> >
> > May this operation race with UFS shutdown flow?
> >
> > To be more clear, ufshcd_wb_ctrl() here may be executed after host
> > clock
> > is disabled by shutdown flow?
> >
> > If yes, we need to avoid it.
> >
> > Thanks,
> > Stanley Chu
>
> Yes, it is quite possible, but who will mess up this on purpose?
>
> ok, to counterbalance our concerns, I can add checkup:
>
>
> /* UFS device & link must be active before we change WB status */
> if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba))
> return -EINVAL;
>
>
> how do you think about?
>
> Bean
seems there are only auto_hibern8 and wb will issue command to UFS
device. if you think auto_hibern8 also needs this protection.
I will add in the next version patch, otherwise, just add this checkup
in the WB.
Look forward to your feedback!
Thanks,
Bean
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