From: Christoph Hellwig <hch@lst.de>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: hch@lst.de, linux-nvme@lists.infradead.org, sagi@grimberg.me,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Vidya Sagar <vidyas@nvidia.com>,
kbusch@kernel.org, linux-pci@vger.kernel.org
Subject: Re: [PATCH] nvme/pci: default to simple suspend
Date: Sat, 23 Apr 2022 07:49:38 +0200 [thread overview]
Message-ID: <20220423054938.GA17945@lst.de> (raw)
In-Reply-To: <20220411135850.GA42637@thinkpad>
On Mon, Apr 11, 2022 at 07:28:50PM +0530, Manivannan Sadhasivam wrote:
> PCI core only accepts the quirks for the host devices that could be passed onto
> the PCI device drivers like this one. In this case, this is not a quirk but
> actually an aggressive power saving feature (atleast on the Qcom platforms).
> Moreover, adding a flag to the PCI bus will make it applicable to all the
> child devices of the RC/bridge and that would be wrong.
As you correctly state it is not a device quirk. It describes the
power management applied by the platform. So we do need to communicate
it through the core PM and/or PCI code. Please work with the relevant
maintainers.
> In our case, the same power saving feature is not applicable to all PCI devices
> like WLAN for an example.
This doesn't make sense. Your plaform can't know what device is connected
to a given root port / slot. So you might have different policies per
slot, but that has nothing to do with the Linux drivers for given devices.
parent reply other threads:[~2022-04-23 5:49 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20220411135850.GA42637@thinkpad>]
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