On 9 March 2016 at 23:19, Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > On Wed, Mar 9, 2016 at 7:14 AM, Dave Airlie <airlied@xxxxxxxxx> wrote: >> From: Dave Airlie <airlied@xxxxxxxxxx> >> >> Windows 10 seems to have standardised power control for the >> optimus/powerxpress laptops using PR3 power resource hooks. >> >> I'm not sure this is definitely the correct place to be >> doing this, but it works for me here. >> >> The ACPI device for the GPU I have is \_SB_.PCI0.PEG_.VID_ >> but the power resource hooks are on \_SB_.PCI0.PEG_, so >> this patch creates a new power domain to turn the GPU >> device parent off using standard ACPI calls. >> >> Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> >> --- >> drivers/gpu/vga/vga_switcheroo.c | 54 +++++++++++++++++++++++++++++++++++++++- >> include/linux/vga_switcheroo.h | 3 ++- >> 2 files changed, 55 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c >> index 665ab9f..be32cb2 100644 >> --- a/drivers/gpu/vga/vga_switcheroo.c >> +++ b/drivers/gpu/vga/vga_switcheroo.c >> @@ -42,7 +42,7 @@ >> #include <linux/uaccess.h> >> #include <linux/vgaarb.h> >> #include <linux/vga_switcheroo.h> >> - >> +#include <linux/acpi.h> >> /** >> * DOC: Overview >> * >> @@ -997,3 +997,55 @@ vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev, >> return -EINVAL; >> } >> EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_optimus_hdmi_audio); >> + >> +/* With Windows 10 the runtime suspend/resume can use power >> + resources on the parent device */ >> +static int vga_acpi_switcheroo_runtime_suspend(struct device *dev) >> +{ >> + struct pci_dev *pdev = to_pci_dev(dev); >> + int ret; >> + struct acpi_device *adev; >> + >> + ret = dev->bus->pm->runtime_suspend(dev); >> + if (ret) >> + return ret; >> + >> + ret = acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev); > > You can use ACPI_COMPANION(&pdev->dev) for that. > >> + if (!ret) >> + acpi_device_set_power(adev->parent, ACPI_STATE_D3_COLD); > > Won't that mess up with the PM of the parent? Or do we know that the > parent won't do its own PM? The parent is always going to be pcieport. It doesn't seem to do any runtime PM, I do wonder if pcieport should be doing it's own runtime PM handling, but that is a larger task than I'm thinking to tackle here. Maybe I should be doing pci_set_power_state(pdev->bus->self, PCI_D3cold) ? I'm not really sure. I'm guessing on Windows this all happens automatically. Dave. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html