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Subject: Re: [PATCH 2/2] scsi: ufs: Stop clearing unit attentions
To:     Adrian Hunter <adrian.hunter@intel.com>,
        Jaegeuk Kim <jaegeuk@kernel.org>, linux-kernel@vger.kernel.org,
        linux-scsi@vger.kernel.org, martin.petersen@oracle.com
Cc:     Bart Van Assche <bvanassche@google.com>
References: <20210930195237.1521436-1-jaegeuk@kernel.org>
 <20210930195237.1521436-2-jaegeuk@kernel.org>
 <12ba3462-ac6b-ef35-4b5e-e0de6086ab51@intel.com>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <e60a9acc-f53e-83b4-8add-b7a53cfd6492@acm.org>
Date:   Fri, 1 Oct 2021 09:19:37 -0700
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On 9/30/21 9:58 PM, Adrian Hunter wrote:
> On 30/09/2021 22:52, Jaegeuk Kim wrote:
>> From: Bart Van Assche <bvanassche@google.com>
>>
>> Commit aa53f580e67b ("scsi: ufs: Minor adjustments to error handling")
>> introduced a ufshcd_clear_ua_wluns() call in
>> ufshcd_err_handling_unprepare(). As explained in detail by Adrian Hunter,
>> this can trigger a deadlock. Avoid that deadlock by removing the code that
>> clears the unit attention. This is safe because the only software that
>> relies on clearing unit attentions is the Android Trusty software and
> 
> Did you test this?

This patch series has been tested on an Android phone running the latest Trusty
software but with runtime power management disabled.

Bart.