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Subject: Re: [PATCH v20 1/2] scsi: ufs: Enable power management for wlun
To:     Adrian Hunter <adrian.hunter@intel.com>, cang@codeaurora.org,
        martin.petersen@oracle.com, linux-scsi@vger.kernel.org
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 <fdadd467-b613-d800-18c5-be064396fd10@intel.com>
From:   "Asutosh Das (asd)" <asutoshd@codeaurora.org>
Message-ID: <07e3ea07-e1c3-7b8c-e398-8b008f873e6d@codeaurora.org>
Date:   Mon, 19 Apr 2021 14:53:50 -0700
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On 4/19/2021 11:37 AM, Adrian Hunter wrote:
> On 16/04/21 10:49 pm, Asutosh Das wrote:
>>
>> Co-developed-by: Can Guo <cang@codeaurora.org>
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
>> ---
> 
> I came across 3 issues while testing.  See comments below.
> 
Hi Adrian
Thanks for the comments.
> <SNIP>
> 
>> @@ -5794,7 +5839,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
>>   	if (ufshcd_is_clkscaling_supported(hba))
>>   		ufshcd_clk_scaling_suspend(hba, false);
>>   	ufshcd_clear_ua_wluns(hba);
> 
> ufshcd_clear_ua_wluns() deadlocks trying to clear UFS_UPIU_RPMB_WLUN
> if sdev_rpmb is suspended and sdev_ufs_device is suspending.
> e.g. ufshcd_wl_suspend() is waiting on host_sem while ufshcd_err_handler()
> is running, at which point sdev_rpmb has already suspended.
> 
Umm, I didn't understand this deadlock.
When you say, sdev_rpmb is suspended, does it mean runtime_suspended?
sdev_ufs_device is suspending - this can't be runtime_suspending, while 
ufshcd_err_handling_unprepare is running.

If you've a call-stack of this deadlock, please can you share it with 
me. I'll also try to reproduce this.

I'll address the other comments in the next version.


Thank you!

>> -	pm_runtime_put(hba->dev);
>> +	ufshcd_rpm_put(hba);
>>   }
> 
> <SNIP>
> 
>> +void ufshcd_resume_complete(struct device *dev)
>> +{

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