[AMD Public Use] > -----Original Message----- > From: Lukas Wunner <lukas@xxxxxxxxx> > Sent: Friday, October 2, 2020 1:10 AM > To: Bjorn Helgaas <helgaas@xxxxxxxxxx>; Rafael J. Wysocki > <rjw@xxxxxxxxxxxxx>; Len Brown <lenb@xxxxxxxxxx> > Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Mika Westerberg > <mika.westerberg@xxxxxxxxxxxxxxx>; linux-pci@xxxxxxxxxxxxxxx; linux- > acpi@xxxxxxxxxxxxxxx; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Arthur Borsboom > <arthurborsboom@xxxxxxxxx>; matoro <matoro@xxxxxxxxxx>; Aaron > Zakhrov <aaron.zakhrov@xxxxxxxxx>; Michal Rostecki > <mrostecki@xxxxxxxx>; Shai Coleman <git@xxxxxxxxxxxxxxx> > Subject: [PATCH] PCI/ACPI: Whitelist hotplug ports for D3 if power managed > by ACPI > > Recent laptops with dual AMD GPUs fail to suspend the discrete GPU, thus > causing lockups on system sleep and high power consumption at runtime. > The discrete GPU would normally be suspended to D3cold by turning off > ACPI _PR3 Power Resources of the Root Port above the GPU. > > However on affected systems, the Root Port is hotplug-capable and > pci_bridge_d3_possible() only allows hotplug ports to go to D3 if they belong > to a Thunderbolt device or if the Root Port possesses a > "HotPlugSupportInD3" ACPI property. Neither is the case on affected > laptops. The reason for whitelisting only specific, known to work hotplug > ports for D3 is that there have been reports of SkyLake Xeon-SP systems > raising Hardware Error NMIs upon suspending their hotplug ports: > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore. > kernel.org%2Flinux-pci%2F20170503180426.GA4058%40otc-nc- > 03%2F&data=02%7C01%7Calexander.deucher%40amd.com%7C712c82d > abd82477e540408d8669172c3%7C3dd8961fe4884e608e11a82d994e183d%7C0 > %7C0%7C637372123238938344&sdata=S1%2ByqWpkuZcilrl7kRXQyodrN > P66MAjcECRDd7tEjpE%3D&reserved=0 > > But if a hotplug port is power manageable by ACPI (as can be detected > through presence of Power Resources and corresponding _PS0 and _PS3 > methods) then it ought to be safe to suspend it to D3. To this end, amend > acpi_pci_bridge_d3() to whitelist such ports for D3. > > Link: > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitla > b.freedesktop.org%2Fdrm%2Famd%2F- > %2Fissues%2F1222&data=02%7C01%7Calexander.deucher%40amd.com > %7C712c82dabd82477e540408d8669172c3%7C3dd8961fe4884e608e11a82d99 > 4e183d%7C0%7C0%7C637372123238938344&sdata=k%2FRI8kSJclwhzYuc > WSjAZNzNEaaU9JgIYNjJsV0dAWo%3D&reserved=0 > Link: > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitla > b.freedesktop.org%2Fdrm%2Famd%2F- > %2Fissues%2F1252&data=02%7C01%7Calexander.deucher%40amd.com > %7C712c82dabd82477e540408d8669172c3%7C3dd8961fe4884e608e11a82d99 > 4e183d%7C0%7C0%7C637372123238938344&sdata=JvakgHaQNI6XMaM > eTHqtPJ5ooZP83lN%2F6wcdHyt53yA%3D&reserved=0 > Link: > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitla > b.freedesktop.org%2Fdrm%2Famd%2F- > %2Fissues%2F1304&data=02%7C01%7Calexander.deucher%40amd.com > %7C712c82dabd82477e540408d8669172c3%7C3dd8961fe4884e608e11a82d99 > 4e183d%7C0%7C0%7C637372123238938344&sdata=8clLa%2BCnwH4xtK > Dc7F9%2FqPBSMFygpjP8EiPgVIz9LiE%3D&reserved=0 > Reported-and-tested-by: Arthur Borsboom <arthurborsboom@xxxxxxxxx> > Reported-and-tested-by: matoro <matoro@xxxxxxxxxx> > Reported-by: Aaron Zakhrov <aaron.zakhrov@xxxxxxxxx> > Reported-by: Michal Rostecki <mrostecki@xxxxxxxx> > Reported-by: Shai Coleman <git@xxxxxxxxxxxxxxx> > Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Cc: Alex Deucher <alexander.deucher@xxxxxxx> > Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> Thanks for sorting this out. Acked-by: Alex Deucher <alexander.deucher@xxxxxxx> > --- > drivers/pci/pci-acpi.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index > d5869a0..d9aa551 100644 > --- a/drivers/pci/pci-acpi.c > +++ b/drivers/pci/pci-acpi.c > @@ -944,6 +944,16 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev) > if (!dev->is_hotplug_bridge) > return false; > > + /* Assume D3 support if the bridge is power-manageable by ACPI. */ > + adev = ACPI_COMPANION(&dev->dev); > + if (!adev && !pci_dev_is_added(dev)) { > + adev = acpi_pci_find_companion(&dev->dev); > + ACPI_COMPANION_SET(&dev->dev, adev); > + } > + > + if (adev && acpi_device_power_manageable(adev)) > + return true; > + > /* > * Look for a special _DSD property for the root port and if it > * is set we know the hierarchy behind it supports D3 just fine. > -- > 2.27.0
