linux-kernel - Re: [PATCH v6 5/9] tpm, tpm_tis: Only handle supported interrupts

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Date:   Wed, 29 Jun 2022 11:20:47 +0200
From:   Lino Sanfilippo <LinoSanfilippo@....de>
To:     Jarkko Sakkinen <jarkko@...nel.org>
Cc:     peterhuewe@....de, jgg@...pe.ca, stefanb@...ux.vnet.ibm.com,
        linux@...ewoehner.de, linux-integrity@...r.kernel.org,
        linux-kernel@...r.kernel.org, l.sanfilippo@...bus.com,
        lukas@...ner.de, p.rosenberger@...bus.com
Subject: Re: [PATCH v6 5/9] tpm, tpm_tis: Only handle supported interrupts



On 28.06.22 01:09, Jarkko Sakkinen wrote:
> On Sun, Jun 26, 2022 at 02:18:17PM +0200, Lino Sanfilippo wrote:
>> On 26.06.22 at 08:40, Jarkko Sakkinen wrote:
>>>
>>> I would instead mask out bits and write a helper function
>>> taking care of this:
>>>
>>> static u8 tpm_tis_filter_sts_mask(u8 int_mask, u8 sts_mask)
>>> {
>>>         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
>>>
>>>         if (!(int_mask & TPM_INTF_STS_VALID_INT))
>>>                 sts_mask &= ~TPM_STS_VALID;
>>>
>>>         if (!(int_mask & TPM_INTF_DATA_AVAIL_INT))
>>>                 sts_mask &= ~TPM_STS_DATA_AVAIL;
>>>
>>>         if (!(int_mask & TPM_INTF_CMD_READY_INT))
>>> 		sts_mask &= ~TPM_STS_COMMAND_READY;
>>>
>>>         return sts_mask;
>>> }
>>>
>>> Less operations and imho somewhat cleaner structure.
>>>
>>> Add suggested-by if you want.
>>
>> I thought of a helper like this before but then decided to
>> not introduce another function to keep the code changes minimal. But yes,
>> it is indeed cleaner. I will do the change and resubmit the series.
>>
>> Thanks for the review!
>>
>> Regards,
>> Lino
>
> Yeah, please don't add suggested-by, it's such a minor detail
> in the overall patch :-)

I already created a separate patch which only contains moving the bit checks into the
helper function. For that patch the Suggested-by is fully justified IMHO.


Thanks for taking time to fix these
> glitches and also taking all the feedback into account (and
> also being patient).
>

No problem. Its always good to have some feedback from people that have a deeper insight
into the code. Especially when it is as complex as the TPM subsystem and drivers.

Best regards,
Lino