[PATCH v4 2/2] nvme-pci: add AMD PCIe quirk for suspend/resume

[Liang, Prike]

[AMD Public Use]

> From: Greg KH <gregkh at linuxfoundation.org>
> Sent: Thursday, April 15, 2021 2:30 PM
> To: Liang, Prike <Prike.Liang at amd.com>
> Cc: linux-nvme at lists.infradead.org; Chaitanya.Kulkarni at wdc.com;
> hch at infradead.org; stable at vger.kernel.org; Deucher, Alexander
> <Alexander.Deucher at amd.com>; S-k, Shyam-sundar <Shyam-sundar.S-
> k at amd.com>
> Subject: Re: [PATCH v4 2/2] nvme-pci: add AMD PCIe quirk for
> suspend/resume
>
> On Thu, Apr 15, 2021 at 11:52:05AM +0800, Prike Liang wrote:
> > The NVME device pluged in some AMD PCIE root port will resume timeout
> > from s2idle which caused by NVME power CFG lost in the SMU FW restore.
> > This issue can be workaround by using PCIe power set with simple
> > suspend/resume process path instead of APST. In the onwards ASIC will
> > try do the NVME shutdown save and restore in the BIOS and still need
> > PCIe power setting to resume from RTD3 for s2idle.
> >
> > Update the nvme_acpi_storage_d3() _with previously added quirk.
> >
> > Cc: <stable at vger.kernel.org> # 5.11+
> > 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>
> >
> > Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
>
> You don't sign off and review a patch.  And you do not put a blank line
> between them, this should all be one chunk of text.
>
>
>
> > ---
> > 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.
> > ---
> >  drivers/nvme/host/pci.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index
> > 6bad4d4..ce9f42b 100644
> > --- a/drivers/nvme/host/pci.c
> > +++ b/drivers/nvme/host/pci.c
> > @@ -2832,6 +2832,7 @@ static bool nvme_acpi_storage_d3(struct pci_dev
> > *dev)  {
> >  struct acpi_device *adev;
> >  struct pci_dev *root;
> > +struct pci_dev *rdev;
> >  acpi_handle handle;
> >  acpi_status status;
> >  u8 val;
> > @@ -2845,6 +2846,12 @@ static bool nvme_acpi_storage_d3(struct
> pci_dev *dev)
> >  if (!root)
> >  return false;
> >
> > +rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
>
> Please look at the root bus for the specific device, do not assume that you
> are only on this specific bus.
>
Thanks proposal, do you mean search the root complex device should by NVMe RP bus and something like as the following?
rdev = pci_get_domain_bus_and_slot(pci_domain_nr(root->bus), root->bus->number, PCI_DEVFN(0, 0));

> greg k-h