Re: [PATCH V2] PCI: rcar: Add the initialization of PCIe link in resume_noirq

[Marek Vasut <marek.vasut@gmail.com>]

On 3/22/19 12:31 PM, Lorenzo Pieralisi wrote:
> On Sun, Feb 17, 2019 at 02:24:41PM +0100, marek.vasut@gmail.com wrote:
>> From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com>
>>
>> Reestablish the PCIe link very early in the resume process in case it
>> went down to prevent PCI accesses from hanging the bus. Such accesses
> 
> Hi Marek, Kazufumi,

Hi,

> Apologies for the delay.
> 
> Just as a clarification, when you state "in case it went down" isn't
> this supposed to happen for every suspend cycle ? Let me know and I
> will add a comment to the patch commit log.

It does happen on every suspend/resume cycle and if you manually put a
remote endpoint into non-L0 state.

>> can happen early in the PCI resume process, in the resume_noirq, thus
>> the link must be reestablished in the resume_noirq callback of the
>> driver.
>>
>> Signed-off-by: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com>
>> Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
>> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
>> Cc: Phil Edworthy <phil.edworthy@renesas.com>
>> Cc: Simon Horman <horms+renesas@verge.net.au>
>> Cc: Wolfram Sang <wsa@the-dreams.de>
>> Cc: linux-renesas-soc@vger.kernel.org
> 
> This looks like a fix (most likely fixing initial S2R support, please
> help me chase the commit ID), should we consider it for stable kernels ?
> 
> Without it I understand S2R is actually broken on platforms with this
> host bridge.
I don't think this ever worked, so it's hard to find a Fixes: commit for
this.

-- 
Best regards,
Marek Vasut