5.4-stable review patch. If anyone has any objections, please let me know.
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From: Maxim Mikityanskiy maxtram95@gmail.com
[ Upstream commit 2b360ba9a4936486380bc30d1eabceb40a714d98 ]
quirk_nvidia_hda() forcefully enables HDA controller on all NVIDIA GPUs, because some buggy BIOSes leave it disabled. However, some dual-GPU laptops do not have a functional HDA controller in DGPU, and BIOS disables it on purpose. After quirk_nvidia_hda() reenables this dummy HDA controller, attempting to probe it fails at azx_first_init(), which is too late to cancel the probe, as it happens in azx_probe_continue().
The sna_hda_intel driver calls azx_free() and stops the chip, however, it stays probed, and from the runtime PM point of view, the device remains active (it was set as active by the PCI subsystem on probe). It prevents vga_switcheroo from turning off the DGPU, because pci_create_device_link() syncs power management for video and audio devices.
Affected devices should be added to driver_denylist to prevent them from probing early. This patch helps identify such devices by printing a warning, and also forces the device to the suspended state to allow vga_switcheroo turn off DGPU.
Signed-off-by: Maxim Mikityanskiy maxtram95@gmail.com Link: https://patch.msgid.link/20250208214602.39607-2-maxtram95@gmail.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/pci/hda/hda_intel.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 59fc56a970a9d..cdc1d00ab34b1 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1410,8 +1410,21 @@ static void azx_free(struct azx *chip) if (use_vga_switcheroo(hda)) { if (chip->disabled && hda->probe_continued) snd_hda_unlock_devices(&chip->bus); - if (hda->vga_switcheroo_registered) + if (hda->vga_switcheroo_registered) { vga_switcheroo_unregister_client(chip->pci); + + /* Some GPUs don't have sound, and azx_first_init fails, + * leaving the device probed but non-functional. As long + * as it's probed, the PCI subsystem keeps its runtime + * PM status as active. Force it to suspended (as we + * actually stop the chip) to allow GPU to suspend via + * vga_switcheroo, and print a warning. + */ + dev_warn(&pci->dev, "GPU sound probed, but not operational: please add a quirk to driver_denylist\n"); + pm_runtime_disable(&pci->dev); + pm_runtime_set_suspended(&pci->dev); + pm_runtime_enable(&pci->dev); + } }
if (bus->chip_init) {