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From:   Jerry Snitselaar <jsnitsel@redhat.com>
Mime-Version: 1.0 (1.0)
Subject: Re: [PATCH] idxd: avoid deadlock in process_misc_interrupts()
Date:   Mon, 12 Dec 2022 13:08:23 -0700
Message-Id: <446A5C1E-E50B-4270-9781-5D945109541E@redhat.com>
References: <IA1PR11MB6097183F44E96BE3FAF119DA9BE29@IA1PR11MB6097.namprd11.prod.outlook.com>
Cc:     linux-kernel@vger.kernel.org, "Jiang, Dave" <dave.jiang@intel.com>,
        Vinod Koul <vkoul@kernel.org>, dmaengine@vger.kernel.org
In-Reply-To: <IA1PR11MB6097183F44E96BE3FAF119DA9BE29@IA1PR11MB6097.namprd11.prod.outlook.com>
To:     "Yu, Fenghua" <fenghua.yu@intel.com>
Precedence: bulk


> On Dec 12, 2022, at 11:47 AM, Yu, Fenghua <fenghua.yu@intel.com> wrote:
>=20
> =EF=BB=BFHi, Jerry,
>=20
>> idxd_device_clear_state() now grabs the idxd->dev_lock itself, so don't g=
rab the
>> lock prior to calling it.
>>=20
>> This was seen in testing after dmar fault occurred on system, resulting i=
n lockup
>> stack traces.
>>=20
>=20
> Please add Fixes: cf4ac3fef338 ...
>=20
>> Cc: Fenghua Yu <fenghua.yu@intel.com>
>> Cc: Dave Jiang <dave.jiang@intel.com>
>> Cc: Vinod Koul <vkoul@kernel.org>
>> Cc: dmaengine@vger.kernel.org
>> Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
>> ---
>> drivers/dma/idxd/irq.c | 2 --
>> 1 file changed, 2 deletions(-)
>>=20
>> diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c index
>> 743ead5ebc57..5b9921475be6 100644
>> --- a/drivers/dma/idxd/irq.c
>> +++ b/drivers/dma/idxd/irq.c
>> @@ -324,13 +324,11 @@ static int process_misc_interrupts(struct idxd_devi=
ce
>> *idxd, u32 cause)
>>            idxd->state =3D IDXD_DEV_HALTED;
>>            idxd_wqs_quiesce(idxd);
>>            idxd_wqs_unmap_portal(idxd);
>> -            spin_lock(&idxd->dev_lock);
>>            idxd_device_clear_state(idxd);
>>            dev_err(&idxd->pdev->dev,
>>                "idxd halted, need %s.\n",
>>                gensts.reset_type =3D=3D IDXD_DEVICE_RESET_FLR ?
>>                "FLR" : "system reset");
>> -            spin_unlock(&idxd->dev_lock);
>>            return -ENXIO;
>>        }
>>    }
>> --
>> 2.37.2
>=20
> Thanks.
>=20
> -Fenghua
>=20

Hi Fenghua,

I think this was merged back in August. Not at my system to get the exact da=
te.

Regards,
Jerry=