On 2020/4/14 下午8:41, Takashi Iwai wrote:
On Tue, 14 Apr 2020 14:40:35 +0200,
Takashi Iwai wrote:
On Tue, 14 Apr 2020 14:35:50 +0200,
Hui Wang wrote:
On 2020/4/14 下午6:27, Takashi Iwai wrote:
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@xxxxxxxxxxxxx>
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.
Oh, I don't know that, according to my test with ubuntu rootfs, the
runtime pm is not enabled on Intel's hda controllers. But with the sof
driver, the controller driver calls runtime_allow()
(soc/sof/sof-pci-dev.c), so I sent this patch.
OK, I just watned to know the situation. So it's no regression but
rather to align the behavior among drivers, and that's fine.
Let's take the patch, then.
On the second thought, we can drop the vga_switcheroo check and always
allow it? We do want to enable in anyway, and calling it twice should
be fine.
Yes, could drop the check, it is fine to call runtime_allow() twice.
Thanks,
Hui.
thanks,
Takashi
thanks,
Takashi
Regards,
Hui.
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);
pm_runtime_put_autosuspend(&pci->dev);
}
--
2.17.1
