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Date:   Tue, 23 May 2023 12:41:24 +0200
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Subject: Re: [PATCH 1/2] tpm, tpm_tis: Handle interrupt storm
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To:     =?UTF-8?Q?P=c3=a9ter_Ujfalusi?= <peter.ujfalusi@linux.intel.com>,
        Lukas Wunner <lukas@wunner.de>
Cc:     Lino Sanfilippo <LinoSanfilippo@gmx.de>, peterhuewe@gmx.de,
        jarkko@kernel.org, jgg@ziepe.ca, jsnitsel@redhat.com,
        hdegoede@redhat.com, oe-lkp@lists.linux.dev, lkp@intel.com,
        peterz@infradead.org, linux@mniewoehner.de,
        linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        p.rosenberger@kunbus.com
References: <20230522143105.8617-1-LinoSanfilippo@gmx.de>
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From:   Lino Sanfilippo <l.sanfilippo@kunbus.com>
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Hi,

On 23.05.23 11:14, Péter Ujfalusi wrote:

>>
>>>>     rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
>>>>     tpm_tis_relinquish_locality(chip, 0);
>>>>     if (rc < 0)
>>>> -           return IRQ_NONE;
>>>> +           goto unhandled;
>>>
>>> This is more like an error than just unhandled IRQ. Yes, it was ignored,
>>> probably because it is common?
>>
>> The interrupt may be shared and then it's not an error.
> 
> but this is tpm_tis_write32() failing, no? If it is shared interrupt and
> we return IRQ_HANDLED unconditionally then I think the core will think
> that the interrupt was for this device and it was handled.
> 

At this point we already know the interrupt was for our device. Otherwise we would
have already bailed out at

	if (interrupt == 0)
	

Regards,
Lino


> --
> Péter