On Wed, May 25, 2016 at 12:53:01AM +0200, Peter Wu wrote: > Since "PCI: Add runtime PM support for PCIe ports", the parent PCIe port > can be runtime-suspended which disables power resources via ACPI. This > is incompatible with DSM, resulting in a GPU device which is still in D3 > and locks up the kernel on resume. > > Mirror the behavior of Windows 8 and newer[1] (as observed via an AMLi > debugger trace) and stop using the DSM functions for D3cold when power > resources are available on the parent PCIe port. > > [1]: https://msdn.microsoft.com/windows/hardware/drivers/bringup/firmware-requirements-for-d3cold > > Signed-off-by: Peter Wu <peter@xxxxxxxxxxxxx> > --- > drivers/gpu/drm/nouveau/nouveau_acpi.c | 34 ++++++++++++++++++++++++++++++---- > 1 file changed, 30 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c > index df9f73e..e469df7 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c > +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c > @@ -46,6 +46,7 @@ static struct nouveau_dsm_priv { > bool dsm_detected; > bool optimus_detected; > bool optimus_flags_detected; > + bool optimus_skip_dsm; > acpi_handle dhandle; > acpi_handle rom_handle; > } nouveau_dsm_priv; > @@ -212,8 +213,26 @@ static const struct vga_switcheroo_handler nouveau_dsm_handler = { > .get_client_id = nouveau_dsm_get_client_id, > }; > > +/* Firmware supporting Windows 8 or later do not use _DSM to put the device into > + * D3cold, they instead rely on disabling power resources on the parent. */ > +static bool nouveau_pr3_present(struct pci_dev *pdev) > +{ > + struct pci_dev *parent_pdev = pci_upstream_bridge(pdev); > + struct acpi_device *ad; Nit: please call this adev instead of ad. > + > + if (!parent_pdev) > + return false; > + > + ad = ACPI_COMPANION(&parent_pdev->dev); > + if (!ad) > + return false; > + > + return ad->power.flags.power_resources; Is this sufficient to tell if the parent device has _PR3? I thought it returns true if it has power resources in general, not necessarily _PR3. Otherwise this looks okay to me. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
