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Date:   Wed, 03 Mar 2021 18:06:37 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Avri Altman <Avri.Altman@wdc.com>
Cc:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com, Alim Akhtar <alim.akhtar@samsung.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>
Subject: Re: [PATCH v2 1/3] scsi: ufs: Minor adjustments to error handling
In-Reply-To: <3c6df42fef5a1e52e655753aadec4a11@codeaurora.org>
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 <3c6df42fef5a1e52e655753aadec4a11@codeaurora.org>
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On 2021-03-03 18:03, Can Guo wrote:
> Hi Avri,
> 
> On 2021-03-03 15:22, Avri Altman wrote:
>>> 
>>> 
>>> In error handling prepare stage, after SCSI requests are blocked, do 
>>> a
>>> down/up_write(clk_scaling_lock) to clean up the queuecommand() path.
>>> Meanwhile, stop eeh_work in case it disturbs error recovery. 
>>> Moreover,
>>> reset ufshcd_state at the entrance of ufshcd_probe_hba(), since it 
>>> may be
>>> called multiple times during error recovery.
>>> 
>>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> I noticed that you tagged Adrian's patch -
>> https://lore.kernel.org/lkml/20210301191940.15247-1-adrian.hunter@intel.com/
>> So this patch needs to be adjusted accordingly?
> 
> Thanks for pointing me to that one, I will rebase mine.
> 
> Regards,
> Can Guo.
> 

Just noticed that Adrian's change comes later than mine, so I may not 
need to
adjust mine.

Thanks,
Can Guo.

>> 
>> Thanks,
>> Avri
>> 
>>> ---
>>>  drivers/scsi/ufs/ufshcd.c | 18 ++++++++++++------
>>>  1 file changed, 12 insertions(+), 6 deletions(-)
>>> 
>>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>>> index 80620c8..013eb73 100644
>>> --- a/drivers/scsi/ufs/ufshcd.c
>>> +++ b/drivers/scsi/ufs/ufshcd.c
>>> @@ -4987,6 +4987,7 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba,
>>> struct ufshcd_lrb *lrbp)
>>>                          * UFS device needs urgent BKOPs.
>>>                          */
>>>                         if (!hba->pm_op_in_progress &&
>>> +                           !ufshcd_eh_in_progress(hba) &&
>>>                             
>>> ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
>>>                             schedule_work(&hba->eeh_work)) {
>>>                                 /*
>>> @@ -5784,13 +5785,20 @@ static void 
>>> ufshcd_err_handling_prepare(struct
>>> ufs_hba *hba)
>>>                         ufshcd_suspend_clkscaling(hba);
>>>                 ufshcd_clk_scaling_allow(hba, false);
>>>         }
>>> +       ufshcd_scsi_block_requests(hba);
>>> +       /* Drain ufshcd_queuecommand() */
>>> +       down_write(&hba->clk_scaling_lock);
>>> +       up_write(&hba->clk_scaling_lock);
>>> +       cancel_work_sync(&hba->eeh_work);
>>>  }
>>> 
>>>  static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
>>>  {
>>> +       ufshcd_scsi_unblock_requests(hba);
>>>         ufshcd_release(hba);
>>>         if (ufshcd_is_clkscaling_supported(hba))
>>>                 ufshcd_clk_scaling_suspend(hba, false);
>>> +       ufshcd_clear_ua_wluns(hba);
>>>         pm_runtime_put(hba->dev);
>>>  }
>>> 
>>> @@ -5882,8 +5890,8 @@ static void ufshcd_err_handler(struct 
>>> work_struct
>>> *work)
>>>         spin_unlock_irqrestore(hba->host->host_lock, flags);
>>>         ufshcd_err_handling_prepare(hba);
>>>         spin_lock_irqsave(hba->host->host_lock, flags);
>>> -       ufshcd_scsi_block_requests(hba);
>>> -       hba->ufshcd_state = UFSHCD_STATE_RESET;
>>> +       if (hba->ufshcd_state != UFSHCD_STATE_ERROR)
>>> +               hba->ufshcd_state = UFSHCD_STATE_RESET;
>>> 
>>>         /* Complete requests that have door-bell cleared by h/w */
>>>         ufshcd_complete_requests(hba);
>>> @@ -6042,12 +6050,8 @@ static void ufshcd_err_handler(struct 
>>> work_struct
>>> *work)
>>>         }
>>>         ufshcd_clear_eh_in_progress(hba);
>>>         spin_unlock_irqrestore(hba->host->host_lock, flags);
>>> -       ufshcd_scsi_unblock_requests(hba);
>>>         ufshcd_err_handling_unprepare(hba);
>>>         up(&hba->host_sem);
>>> -
>>> -       if (!err && needs_reset)
>>> -               ufshcd_clear_ua_wluns(hba);
>>>  }
>>> 
>>>  /**
>>> @@ -7858,6 +7862,8 @@ static int ufshcd_probe_hba(struct ufs_hba 
>>> *hba,
>>> bool async)
>>>         unsigned long flags;
>>>         ktime_t start = ktime_get();
>>> 
>>> +       hba->ufshcd_state = UFSHCD_STATE_RESET;
>>> +
>>>         ret = ufshcd_link_startup(hba);
>>>         if (ret)
>>>                 goto out;
>>> --
>>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
>>> Linux
>>> Foundation Collaborative Project.