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Subject: Re: [PATCH v2 2/7] scsi: libsas: only clear phy->in_shutdown after
 shutdown event done
To:     John Garry <john.garry@huawei.com>, <martin.petersen@oracle.com>,
        <jejb@linux.vnet.ibm.com>
References: <20190130082412.9357-1-yanaijie@huawei.com>
 <20190130082412.9357-3-yanaijie@huawei.com>
 <5643a038-a62f-e19c-1073-d845a8344b9f@huawei.com>
CC:     <linux-scsi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <zhaohongjiang@huawei.com>, <hare@suse.com>,
        <dan.j.williams@intel.com>, <jthumshirn@suse.de>, <hch@lst.de>,
        <huangdaode@hisilicon.com>, <chenxiang66@hisilicon.com>,
        <xiexiuqi@huawei.com>, <tj@kernel.org>, <miaoxie@huawei.com>,
        Ewan Milne <emilne@redhat.com>, Tomas Henzl <thenzl@redhat.com>
From:   Jason Yan <yanaijie@huawei.com>
Message-ID: <5C524BC6.3010006@huawei.com>
Date:   Thu, 31 Jan 2019 09:13:42 +0800
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On 2019/1/31 0:26, John Garry wrote:
> On 30/01/2019 08:24, Jason Yan wrote:
>> When the event queue is full of phy up and down events and reached the
>> threshold, we will queue a shutdown-event, and set phy->in_shutdown so
>> that we will not queue a shutdown-event again. But before the
>> shutdown-event can be executed, every phy-down event will clear
>> phy->in_shutdown and a new shutdown-event will be queued. The queue will
>> be full of these shutdown-events.
>>
>> Fix this by only clear phy->in_shutdown in sas_phye_shutdown(), that is
>> after the first shutdown-event has been executed.
>>
>
> Seems ok as a fix:
> Reviewed-by: John Garry <john.garry@huawei.com>
>
> After this fix, could we change to use a static per-PHY shutdown event
> so that we cannot re-queue it? I know that this is going against idea of
> dynamic events, but it's easier than messing with flags like this.
>

Thanks, I will consider this.

>> Fixes: f12486e06ae8 ("scsi: libsas: shut down the PHY if events
>> reached the threshold")
>> Signed-off-by: Jason Yan <yanaijie@huawei.com>
>> CC: John Garry <john.garry@huawei.com>
>> CC: Johannes Thumshirn <jthumshirn@suse.de>
>> CC: Ewan Milne <emilne@redhat.com>
>> CC: Christoph Hellwig <hch@lst.de>
>> CC: Tomas Henzl <thenzl@redhat.com>
>> CC: Dan Williams <dan.j.williams@intel.com>
>> CC: Hannes Reinecke <hare@suse.com>
>> ---
>>  drivers/scsi/libsas/sas_phy.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/scsi/libsas/sas_phy.c
>> b/drivers/scsi/libsas/sas_phy.c
>> index 0374243c85d0..762bb13cca74 100644
>> --- a/drivers/scsi/libsas/sas_phy.c
>> +++ b/drivers/scsi/libsas/sas_phy.c
>> @@ -35,7 +35,6 @@ static void sas_phye_loss_of_signal(struct
>> work_struct *work)
>>      struct asd_sas_event *ev = to_asd_sas_event(work);
>>      struct asd_sas_phy *phy = ev->phy;
>>
>> -    phy->in_shutdown = 0;
>>      phy->error = 0;
>>      sas_deform_port(phy, 1);
>>  }
>> @@ -45,7 +44,6 @@ static void sas_phye_oob_done(struct work_struct *work)
>>      struct asd_sas_event *ev = to_asd_sas_event(work);
>>      struct asd_sas_phy *phy = ev->phy;
>>
>> -    phy->in_shutdown = 0;
>>      phy->error = 0;
>>  }
>>
>> @@ -127,6 +125,7 @@ static void sas_phye_shutdown(struct work_struct
>> *work)
>>      } else
>>          pr_notice("phy%02d is not enabled, cannot shutdown\n",
>>                phy->id);
>> +    phy->in_shutdown = 0;
>>  }
>>
>>  /* ---------- Phy class registration ---------- */
>>
>
>
>
> .
>