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Subject: Re: [PATCH v3 8/9] scsi: ufs: Update the fast abort path in
 ufshcd_abort() for PM requests
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: <1623300218-9454-1-git-send-email-cang@codeaurora.org>
 <1623300218-9454-9-git-send-email-cang@codeaurora.org>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <fa37645b-3c1e-2272-d492-0c2b563131b1@acm.org>
Date:   Fri, 11 Jun 2021 14:02:40 -0700
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On 6/9/21 9:43 PM, Can Guo wrote:
> If PM requests fail during runtime suspend/resume, RPM framework saves the
> error to dev->power.runtime_error. Before the runtime_error gets cleared,
> runtime PM on this specific device won't work again, leaving the device
> either runtime active or runtime suspended permanently.
> 
> When task abort happens to a PM request sent during runtime suspend/resume,
> even if it can be successfully aborted, RPM framework anyways saves the
> (TIMEOUT) error. In this situation, we can leverage error handling to
> recover and clear the runtime_error. So, let PM requests take the fast
> abort path in ufshcd_abort().

How can a PM request fail during runtime suspend/resume? Does such a
failure perhaps indicate an UFS controller bug? I appreciate your work
but I'm wondering whether it's worth to complicate the UFS driver for
issues that should be fixed in the controller instead of in software.

Thanks,

Bart.