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Date:   Mon, 10 Feb 2020 10:00:40 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Avri Altman <Avri.Altman@wdc.com>
Cc:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, rnayak@codeaurora.org,
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        Alim Akhtar <alim.akhtar@samsung.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Bean Huo <beanhuo@micron.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
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        Venkat Gopalakrishnan <venkatg@codeaurora.org>,
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Subject: Re: [PATCH 5/7] scsi: ufs: Fix ufshcd_hold() caused scheduling while
 atomic
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On 2020-02-09 15:48, Avri Altman wrote:
> You didn't address any of my comments to this patch.
> 
> Thanks,
> Avri

Replied in that thread.

Thanks,
Can Guo.

>> 
>> The async version of ufshcd_hold(async == true), which is only called
>> in queuecommand path as for now, is expected to work in atomic 
>> context,
>> thus it should not sleep or schedule out. When it runs into the 
>> condition
>> that clocks are ON but link is still in hibern8 state, it should bail 
>> out
>> without flushing the clock ungate work.
>> 
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
>> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>> Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
>> 
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index bbc2607..e8f7f9d 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -1518,6 +1518,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool 
>> async)
>>                  */
>>                 if (ufshcd_can_hibern8_during_gating(hba) &&
>>                     ufshcd_is_link_hibern8(hba)) {
>> +                       if (async) {
>> +                               rc = -EAGAIN;
>> +                               hba->clk_gating.active_reqs--;
>> +                               break;
>> +                       }
>>                         spin_unlock_irqrestore(hba->host->host_lock, 
>> flags);
>>                         flush_work(&hba->clk_gating.ungate_work);
>>                         spin_lock_irqsave(hba->host->host_lock, 
>> flags);
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> Forum,
>> a Linux Foundation Collaborative Project