From: Kai-Heng Feng kai.heng.feng@canonical.com
[ Upstream commit bacd861452d2be86a4df341b12e32db7dac8021e ]
Nvidia proprietary driver doesn't support runtime power management, so when a user only wants to use the integrated GPU, it's a common practice to let dGPU not to bind any driver, and let its upstream port to be runtime suspended. At the end of runtime suspension the port uses platform power management to disable power through _OFF method of power resource, which is listed by _PR3.
After commit b516ea586d71 ("PCI: Enable NVIDIA HDA controllers"), when the dGPU comes with an HDA function, the HDA won't be suspended if the dGPU is unbound, so the power resource can't be turned off by its upstream port driver.
Commit 37a3a98ef601 ("ALSA: hda - Enable runtime PM only for discrete GPU") only allows HDA to be runtime suspended once GPU is bound, to keep APU's HDA working.
However, HDA on dGPU isn't that useful if dGPU is not bound to any driver. So let's relax the runtime suspend requirement for dGPU's HDA function, to disable the power source to save lots of power.
BugLink: https://bugs.launchpad.net/bugs/1840835 Fixes: b516ea586d71 ("PCI: Enable NVIDIA HDA controllers") Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com Link: https://lore.kernel.org/r/20191018073848.14590-2-kai.heng.feng@canonical.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/pci/hda/hda_intel.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 86a416cdeb29..4e757aa9d322 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1280,11 +1280,17 @@ static void init_vga_switcheroo(struct azx *chip) { struct hda_intel *hda = container_of(chip, struct hda_intel, chip); struct pci_dev *p = get_bound_vga(chip->pci); + struct pci_dev *parent; if (p) { dev_info(chip->card->dev, "Handle vga_switcheroo audio client\n"); hda->use_vga_switcheroo = 1; - chip->bus.keep_power = 1; /* cleared in either gpu_bound op or codec probe */ + + /* cleared in either gpu_bound op or codec probe, or when its + * upstream port has _PR3 (i.e. dGPU). + */ + parent = pci_upstream_bridge(p); + chip->bus.keep_power = parent ? !pci_pr3_present(parent) : 1; chip->driver_caps |= AZX_DCAPS_PM_RUNTIME; pci_dev_put(p); }