On Tue, 14 Apr 2020 12:14:05 +0200, Hui Wang wrote:
Before the pci_driver->probe() is called, the pci subsystem calls runtime_forbib() and runtime_get_sync() on this pci dev, so only call runtime_put_autosuspend() is not enough to enable the runtime_pm on this device.
For controllers with vgaswitcheroo feature, the pci/quirks.c will call runtime_allow() for this dev, then the controllers could enter rt_idle/suspend/resume, but for non-vgaswitcheroo controllers like Intel hda controllers, the runtime_pm is not enabled even it calls put_autosuspend(). Need to call runtime_allow() for those controllers in the hda driver.
Signed-off-by: Hui Wang hui.wang@canonical.com
Was this behavior changed from the earlier kernels? I thought this was left untouched because it's supposed to be set via udev rules or such.
OTOH, enabling the runtime PM is almost mandatory for modern systems, and I'm fine to apply this kind of forcible enablement.
thanks,
Takashi
sound/pci/hda/hda_intel.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 8519051a426e..779705bef88b 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -2356,6 +2356,8 @@ static int azx_probe_continue(struct azx *chip)
if (azx_has_pm_runtime(chip)) { pm_runtime_use_autosuspend(&pci->dev);
if (!use_vga_switcheroo(chip))pm_runtime_allow(&pci->dev);-- 2.17.1