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Subject: Re: [Xen-devel] [PATCH V3 1/2] Drivers/PCI: Export pcie_has_flr()
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Cc:     Christoph Hellwig <hch@infradead.org>,
        Bjorn Helgaas <helgaas@kernel.org>, jgross@suse.com,
        Sinan Kaya <okaya@codeaurora.org>,
        Govinda Tatti <Govinda.Tatti@Oracle.COM>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Satanand Burla <satananda.burla@caviumnetworks.com>,
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        Felix Manlunas <felix.manlunas@caviumnetworks.com>,
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        Derek Chickles <derek.chickles@caviumnetworks.com>,
        Srikanth Jampala <Jampala.Srikanth@cavium.com>,
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        bhelgaas@google.com, xen-devel@lists.xenproject.org,
        boris.ostrovsky@Oracle.COM,
        Raghu Vatsavayi <raghu.vatsavayi@caviumnetworks.com>,
        roger.pau@citrix.com
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From:   Sinan Kaya <okaya@kernel.org>
Message-ID: <8b56c803-f8b7-2bb3-79b5-c7aebda6c87c@kernel.org>
Date:   Mon, 10 Sep 2018 13:04:39 -0400
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On 9/10/2018 5:52 AM, Pasi Kärkkäinen wrote:
> Hi,
> 
> On Sun, Sep 09, 2018 at 10:33:02PM -0400, Sinan Kaya wrote:
>> On 9/9/2018 2:59 PM, Pasi Kärkkäinen wrote:
>>> I noticed pcie_has_flr() has been recently exported in upstream Linux:
>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2d2917f7747805a1f4188672f308d82a8ba01700
>>>
>>> Are there more changes / cleanups planned to these interfaces, as mentioned last year?
>>>
>>> (context: xen-pciback reset/do_flr features upstreaming, which kind of stalled last year when pcie_has_flr() wasn't exported at the time)
>>
>> Exporting pcie_has_flr() is a very simple change which could have been done
>> by the XEN porting effort.
>>
>> Maybe, the right question is what is so special about XEN reset?
>>
>> What feature PCI core is missing to support XEN FLR reset that caused
>> the effort to stall?
>>
> 
> Well one of the reasons probably was because Christoph was planning to deprecate the pcie_has_flr() functionality..
> 
> https://lists.xen.org/archives/html/xen-devel/2017-12/msg01057.html
> https://lists.xen.org/archives/html/xen-devel/2017-12/msg01252.html
> 
> But now that pcie_has_flr() is exported and available I guess it's fine to continue using it also for xen-pciback :)
> 

Yeah, I would go ahead with the implementation. Refactoring can be done
independently.

> 
> Thanks,
> 
> -- Pasi
> 
>