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

[Liang, Prike]

[AMD Public Use]

> From: Greg KH <gregkh at linuxfoundation.org>
> Sent: Wednesday, April 14, 2021 3:49 PM
> To: Liang, Prike <Prike.Liang at amd.com>
> Cc: linux-nvme at lists.infradead.org; kbusch at kernel.org;
> Chaitanya.Kulkarni at wdc.com; hch at infradead.org; S-k, Shyam-sundar
> <Shyam-sundar.S-k at amd.com>; Deucher, Alexander
> <Alexander.Deucher at amd.com>; # 5 . 11+ <stable at vger.kernel.org>
> Subject: Re: [PATCH 2/2] nvme-pci: add AMD PCIe quirk for suspend/resume
>
> On Wed, Apr 14, 2021 at 07:13:15AM +0000, Liang, Prike wrote:
> > [AMD Public Use]
> >
> > > From: Greg KH <gregkh at linuxfoundation.org>
> > > Sent: Wednesday, April 14, 2021 2:40 PM
> > > To: Liang, Prike <Prike.Liang at amd.com>
> > > Cc: linux-nvme at lists.infradead.org; kbusch at kernel.org;
> > > Chaitanya.Kulkarni at wdc.com; hch at infradead.org; S-k, Shyam-sundar
> > > <Shyam-sundar.S-k at amd.com>; Deucher, Alexander
> > > <Alexander.Deucher at amd.com>; # 5 . 11+ <stable at vger.kernel.org>
> > > Subject: Re: [PATCH 2/2] nvme-pci: add AMD PCIe quirk for
> > > suspend/resume
> > >
> > > On Wed, Apr 14, 2021 at 02:20:00PM +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.
> > > >
> > > > Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
> > > > [ck: split patches for nvme and pcie]
> > > > Signed-off-by: Prike Liang <Prike.Liang at amd.com>
> > > > Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k at amd.com>
> > > > Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
> > > > Cc: <stable at vger.kernel.org> # 5.11+
> > > > ---
> > > >  drivers/nvme/host/pci.c | 5 +++++
> > > >  1 file changed, 5 insertions(+)
> > > >
> > > > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> > > > index
> > > > 6bad4d4..5a9a192 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 +2846,10 @@ 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)); if
> > > > +(rdev && (rdev->dev_flags &
> > > PCI_DEV_FLAGS_AMD_NVME_SIMPLE_SUSPEND))
> > > > +return NVME_QUIRK_SIMPLE_SUSPEND;
> > > > +
> > > >  adev = ACPI_COMPANION(&root->dev);  if (!adev)  return false;
> > > > --
> > > > 2.7.4
> > > >
> > >
> > > This is still broken, why resend it?
> > Sorry can't get how come the reference count leaked, could you help give
> more detail about this.
>
> Please read the documentation for the call you are making here.  For once, it
> is actually written down what needs to be done :)
Thanks, get it now and will update the patch.