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Subject: Re: [Xen-devel] [PATCH V3 1/2] Drivers/PCI: Export pcie_has_flr()
 interface
To: =?UTF-8?B?UGFzaSBLw6Rya2vDpGluZW4=?= <pasik@iki.fi>
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>,
 linux-pci@vger.kernel.org, Felix Manlunas
 <felix.manlunas@caviumnetworks.com>, linux-kernel@vger.kernel.org,
 Derek Chickles <derek.chickles@caviumnetworks.com>,
 Srikanth Jampala <Jampala.Srikanth@cavium.com>, JBeulich@suse.com,
 Russell Currey <ruscur@russell.cc>, bhelgaas@google.com,
 xen-devel@lists.xenproject.org, boris.ostrovsky@Oracle.COM,
 Raghu Vatsavayi <raghu.vatsavayi@caviumnetworks.com>, roger.pau@citrix.com
References: <20171208202424.GC12367@bhelgaas-glaptop.roam.corp.google.com>
 <426eeeab-0dcd-8de3-9c5f-a166acf2c130@Oracle.COM>
 <20171212005919.GB30595@bhelgaas-glaptop.roam.corp.google.com>
 <49956aaf-5fd5-939d-5fc7-231ffdb98b70@Oracle.COM>
 <20171213212420.GH30595@bhelgaas-glaptop.roam.corp.google.com>
 <fea075cf-fe6f-0d0b-11e4-4279fbfc280a@Oracle.COM>
 <20171215181801.GU30595@bhelgaas-glaptop.roam.corp.google.com>
 <20171218122629.GA18423@infradead.org> <20180909185944.GC18222@reaktio.net>
 <9ffe43d2-a44b-974c-85c9-9923d71c5dba@kernel.org>
 <20180910095231.GD18222@reaktio.net>
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
> 
>