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authorLukas Wunner <lukas@wunner.de>2018-03-03 10:53:24 +0100
committerLukas Wunner <lukas@wunner.de>2018-03-13 22:57:55 +0100
commitdcac86b7d0be71563d6219ce52c9918e44b84f0a (patch)
tree90ac27bb6d8f85e7bfd72819e0283bffd620c74c /drivers/gpu/vga
parentPCI: Make pci_wakeup_bus() & pci_bus_set_current_state() public (diff)
downloadlinux-dcac86b7d0be71563d6219ce52c9918e44b84f0a.tar.xz
linux-dcac86b7d0be71563d6219ce52c9918e44b84f0a.zip
vga_switcheroo: Update PCI current_state on power change
When cutting power to a GPU and its integrated HDA controller, their cached current_state should be updated to D3cold to reflect reality. We currently rely on the DRM and HDA drivers to do that, however: - The HDA driver updates the current_state in azx_vs_set_state(), which will no longer be called with driver power control once we migrate to device links. (It will still be called with manual power control.) - If the HDA device is not bound, its current_state remains at D0 even though the GPU driver may decide to go to D3cold. - The DRM drivers update the current_state using pci_set_power_state() which can't put the device into a deeper power state than D3hot if the GPU is not deemed power-manageable by the platform (even though it *is* power-manageable by some nonstandard means, such as a _DSM). Centralize updating the current_state of the GPU and HDA controller in vga_switcheroo's ->runtime_suspend hook to overcome these deficiencies. The GPU and HDA controller are two functions of the same PCI device (VGA class device on function 0 and audio device on function 1) and no other PCI devices reside on the same bus since this is a PCIe point-to-point link, so we can just walk the bus and update the current_state of all devices. On ->runtime_resume, the HDA controller is in D0uninitialized state. Resume to D0active and then let it autosuspend as it sees fit. Note that vga_switcheroo_init_domain_pm_ops() is not supposed to be called by hybrid graphics laptops which power down the GPU via its root port's _PR3 resources and consequently vga_switcheroo_runtime_suspend() is not used. On those laptops, the root port is power-manageable by the platform (instead of by a nonstandard means) and the current_state is therefore updated by the PCI core through the following call chain: pci_set_power_state() __pci_complete_power_transition() pci_bus_set_current_state() Resuming to D0active happens through: pci_set_power_state() __pci_start_power_transition() pci_wakeup_bus() Cc: Dave Airlie <airlied@redhat.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Peter Wu <peter@lekensteyn.nl> Tested-by: Kai Heng Feng <kai.heng.feng@canonical.com> # AMD PowerXpress Tested-by: Mike Lothian <mike@fireburn.co.uk> # AMD PowerXpress Tested-by: Denis Lisov <dennis.lissov@gmail.com> # Nvidia Optimus Tested-by: Peter Wu <peter@lekensteyn.nl> # Nvidia Optimus Tested-by: Lukas Wunner <lukas@wunner.de> # MacBook Pro Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://patchwork.freedesktop.org/patch/msgid/8416958482c8c42d6f311ea5c1e5a65ccf21f5db.1520068884.git.lukas@wunner.de
Diffstat (limited to 'drivers/gpu/vga')
-rw-r--r--drivers/gpu/vga/vga_switcheroo.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 3cd153c6d271..09dd40dd1dbe 100644
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -1022,6 +1022,7 @@ static int vga_switcheroo_runtime_suspend(struct device *dev)
vgasr_priv.handler->switchto(VGA_SWITCHEROO_IGD);
mutex_unlock(&vgasr_priv.mux_hw_lock);
}
+ pci_bus_set_current_state(pdev->bus, PCI_D3cold);
vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_OFF);
mutex_unlock(&vgasr_mutex);
return 0;
@@ -1035,6 +1036,7 @@ static int vga_switcheroo_runtime_resume(struct device *dev)
mutex_lock(&vgasr_mutex);
vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_ON);
mutex_unlock(&vgasr_mutex);
+ pci_wakeup_bus(pdev->bus);
ret = dev->bus->pm->runtime_resume(dev);
if (ret)
return ret;