[PATCH v5 2/2] nvme-pci: add AMD PCIe quirk for simple suspend/resume

[Liang, Prike]

[AMD Public Use]

+ linux-pci for further review.

Thanks,
> -----Original Message-----
> From: Liang, Prike <Prike.Liang at amd.com>
> Sent: Thursday, April 22, 2021 9:19 AM
> To: linux-nvme at lists.infradead.org; kbusch at kernel.org; hch at infradead.org;
> Chaitanya.Kulkarni at wdc.com; gregkh at linuxfoundation.org
> Cc: stable at vger.kernel.org; Deucher, Alexander
> <Alexander.Deucher at amd.com>; S-k, Shyam-sundar <Shyam-sundar.S-
> k at amd.com>; Liang, Prike <Prike.Liang at amd.com>; Chaitanya Kulkarni
> <chaitanya.kulkarni at wdc.com>
> Subject: [PATCH v5 2/2] nvme-pci: add AMD PCIe quirk for simple
> suspend/resume
>
> In the NVMe controller default suspend-resume seems only save/restore the
> NVMe link state by APST opt and the NVMe remains in D0 during this time.
> Then the NVMe device will be shutdown by SMU firmware in the s2idle entry
> and then will lost the NVMe power context during s2idle resume.Finally, the
> NVMe command queue request will be processed abnormally and result in
> access timeout.This issue can be settled by using PCIe power set with simple
> suspend-resume process path instead of APST get/set opt.
>
> This patch is updating the nvme_acpi_storage_d3() with previously added
> quirk.
>
> Cc: <stable at vger.kernel.org> # 5.10+
> Signed-off-by: Prike Liang <Prike.Liang at amd.com>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k at amd.com>
> [ck: split patches for nvme and pcie]
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
> Suggested-by: Keith Busch <kbusch at kernel.org>
> Acked-by: Keith Busch <kbusch at kernel.org>
> ---
> Changes in v2:
> Fix the patch format and check chip root complex DID instead of PCIe RP to
> avoid the storage device plugged in internal PCIe RP by USB adaptor.
>
> Changes in v3:
> According to Christoph Hellwig do NVME PCIe related identify opt better in
> PCIe quirk driver rather than in NVME module.
>
> Changes in v4:
> Split the fix to PCIe and NVMe part and then call the pci_dev_put() put the
> device reference count and finally refine the commit info.
>
> Changes in v5:
> According to Christoph Hellwig and Keith Busch better use a passthrough
> device(bus) gloable flag to identify the NVMe shutdown opt rather than look
> up the device BDF.
> ---
>  drivers/nvme/host/pci.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index
> 6bad4d4..617256e 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -2836,6 +2836,8 @@ static bool nvme_acpi_storage_d3(struct pci_dev
> *dev)
>  acpi_status status;
>  u8 val;
>
> +if (dev->bus->bus_flags & PCI_BUS_FLAGS_DISABLE_ON_S2I)
> +return true;
>  /*
>   * Look for _DSD property specifying that the storage device on the
> port
>   * must use D3 to support deep platform power savings during
> --
> 2.7.4