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Date:   Thu, 17 Feb 2022 08:12:04 +0530
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Subject: Re: [PATCH v3] nvme/pci: Add quick suspend quirk for Sc7280 Platform
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To:     "Nitin Rawat (QUIC)" <quic_nitirawa@quicinc.com>,
        Christoph Hellwig <hch@infradead.org>,
        Keith Busch <kbusch@kernel.org>,
        "rjw@rjwysocki.net" <rjw@rjwysocki.net>
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        "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
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From:   Vidya Sagar <vidyas@nvidia.com>
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On 2/16/2022 9:39 PM, Nitin Rawat (QUIC) wrote:
> External email: Use caution opening links or attachments
> 
> 
> Hi Christoph/Keith/Rafael
> 
> Since we are giving control to PCIe (NVMe power rails control), it can vary from platform to platform.
> More over, PCIe driver doesn't control these power rails directly from PCIe driver, they tie nvme supply with one of the pcie supply and control them together.
> So i think it would be better to either have quirk based on platform or always setting simple suspend and platform which needs full suspend can update it through some means.
Agree with this comment.
I pushed a similar patch for Tegra platforms @ 
https://lore.kernel.org/linux-nvme/20220217023635.8963-1-vidyas@nvidia.com/T/#u

- Vidya Sagar
> 
> Based on below link, Looks like this can be across platform ...vidya also mention similar concern for tegra platform.
> https://lore.kernel.org/lkml/20220209202639.GB1616420@dhcp-10-100-145-180.wdc.com/T/#md10b0108b3ccbb1254fe0ad8dbb6e98044a8820b
> 
> Please let me know your opinions.
> 
> Thanks,
> Nitin
> -----Original Message-----
> From: Christoph Hellwig <hch@infradead.org>
> Sent: Friday, February 11, 2022 11:53 AM
> To: Nitin Rawat (QUIC) <quic_nitirawa@quicinc.com>
> Cc: Keith Busch <kbusch@kernel.org>; Jens Axboe <axboe@fb.com>; Sagi Grimberg <sagi@grimberg.me>; linux-nvme@lists.infradead.org; linux-kernel@vger.kernel.org; Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>
> Subject: Re: [PATCH v3] nvme/pci: Add quick suspend quirk for Sc7280 Platform
> 
> On Fri, Feb 11, 2022 at 02:23:28AM +0530, Nitin Rawat wrote:
>> Enable quick suspend quirks for Sc7280 platform, where power to nvme
>> device is removed during suspend-resume process. This is done to avoid
>> the failure dring resume.
> 
> You need to sort this out in the PCI and PM layers.  The broken platform will also affect all other PCIe drivers and not just nvme.
>