Re: [PATCH] nvme-pci: Force NVME_QUIRK_SIMPLE_SUSPEND on Qualcomm hosts

[Christoph Hellwig <hch@lst.de>]

On Thu, Oct 24, 2024 at 07:33:07PM +0200, Konrad Dybcio wrote:
> From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> 
> The Qualcomm SC8280XP SoC requires that all PCIe hosts are powered down
> before the platform can reach S3-like sleep states. This is very much
> similar in nature to the issue described in [1].
> 
> Other Qualcomm platforms we support upstream require more complex code
> additions across both the PCIe RC driver and other platform-specific
> ones, before the link can be sustained in suspend. Hence, they
> effectively need the same treatment for now.
> 
> Force NVME_QUIRK_SIMPLE_SUSPEND on all Qualcomm platforms (as
> identified by the upstream bridge having a Qualcomm VID) to address
> that. Once the aforementioned issues on non-SC8280XP platforms are
> addressed, the condition will be made more specific, with a PID check
> limiting it to only the platform(s) that require it due to HW design.

The NVMe driver is the wrong place for this, it needs to happen in the
core by making acpi_storage_d3() evaluate to true.  Preferably by
actually setting the right ACPI attributes because a check for 
PCI vendor ID absolutely will never do the right thing in the long run.