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Subject: Re: [PATCH V4 27/28] PCI: tegra: Add support for GPIO based PERST#
To:     Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
CC:     Thierry Reding <thierry.reding@gmail.com>, <bhelgaas@google.com>,
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From:   Manikanta Maddireddy <mmaddireddy@nvidia.com>
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Date:   Mon, 17 Jun 2019 15:57:09 +0530
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On 17-Jun-19 3:18 PM, Lorenzo Pieralisi wrote:
> On Fri, Jun 14, 2019 at 10:53:13PM +0530, Manikanta Maddireddy wrote:
>
> [...]
>
>>> Ok. My point then is that you have no way to enforce this requirement on
>>> platforms that actually need it, I do not even know if there is a
>>> way you can do it (I was thinking along the lines of using a
>>> compatible string to detect whether the GPIO #PERST reset is mandatory)
>>> but maybe this is not even a SOC property.
>>>
>>> Maybe what I am asking is overkill, I just wanted to understand.
>>>
>>> I was just asking a question to understand how you handle the case
>>> where a GPIO pin definition is missing in DT for a platform that
>>> actually needs it, the driver will probe but nothing will work.
>>>
>>> It would be good to describe this and capture it in the commit log.
>>>
>>> Thanks,
>>> Lorenzo
>> I can't think of a easy way to enforce this requirement. As you said
>> compatible string is per SOC, so we can't use it for a platform.
>> This issue is present on only one platform, so it is hard to miss the
>> DT property. That is the reason for publishing this patch with out this
>> enforcement in driver.
>>
>> I thought for changing PERST# to GPIO for all platform, but testing is
>> a tedious job. Also I don't have Tegra20 and Tegra30 platforms.
> I can't help with that.
>
>> Do you want me to drop the patch or update the limitation in the commit
>> log?
> It is Thierry's call, if he is OK with it fine by me, please do
> update the commit log, it will help everybody understand.
>
> Lorenzo

Sure, I will update the commit log in V5.
Please let me know if you completed reviewing this series, I will
send V5 addressing review comments in this patch.

Manikanta