On Thursday, March 10, 2016 07:56:41 AM Dave Airlie wrote:
On 9 March 2016 at 23:19, Rafael J. Wysocki rafael@kernel.org wrote:
On Wed, Mar 9, 2016 at 7:14 AM, Dave Airlie airlied@gmail.com wrote:
From: Dave Airlie airlied@redhat.com
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@redhat.com
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.
I see.
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.
PCIe ports don't do PM - yet. Mika has posted a series of patches to implement that, however, that are waiting for comments now:
https://patchwork.kernel.org/patch/8453311/ https://patchwork.kernel.org/patch/8453381/ https://patchwork.kernel.org/patch/8453391/ https://patchwork.kernel.org/patch/8453411/ https://patchwork.kernel.org/patch/8453371/ https://patchwork.kernel.org/patch/8453351/
Maybe I should be doing
pci_set_power_state(pdev->bus->self, PCI_D3cold) ? I'm not really sure.
Using pci_set_power_state() would be more appropriate IMO, but you can get to the bridge via dev->parent too, can't you?
In any case, it looks like you and Mika need to talk. :-)
I'm guessing on Windows this all happens automatically.
PCIe ports are power-managend by (newer) Windows AFAICS, but we know for a fact that this simply doesn't work reliably on some older hardware which is why we don't do that. I suppose that the Windows in question uses a cut-off date or similar to decide what do do with PCIe ports PM.
Thanks, Rafael