On Monday 23 April 2018 16:04:55 Kai Heng Feng wrote:
On Apr 20, 2018, at 8:10 PM, Takashi Iwai tiwai@suse.de wrote:
On Fri, 20 Apr 2018 11:44:32 +0200, Kai-Heng Feng wrote:
Now it's a typical discrete-only system. HDMI audio comes from AMD audio controller, others from Intel audio controller.
When SG is enabled, the unused AMD audio contoller still exposes its sysfs, so userspace still opens the control file and stream. If userspace tries to output sound through the stream, it hangs the system.
Hm, could you give more information about how it hangs?
Well, I should say "it hangs the userspace process" instead.
$ speaker-test -t wav -c 2 -D hw:CARD=HDMI,DEV=3 ...and it just stopped. Can't Ctrl+C to break it.
So userspace process cannot be killed at all? Then it is different bug in kernel and disabling pci device is just a workaround. Not a real fix.
I would propose to find out what happen and why it cannot be killed (probably it stuck somewhere in kernel) and fix it properly.
@@ -1627,6 +1629,42 @@ static void check_msi(struct azx *chip) } }
+#if IS_ENABLED(CONFIG_DELL_LAPTOP)
This should be IS_REACHABLE(), as both dell-laptop and HD-audio are tristate.
Thanks, will update in next version.
+static bool check_dell_switchable_gfx(struct pci_dev *pdev)
I'd remove "_dell" word here. Such a check would be likely needed for other vendors, and it's quite possible that the function will be extended to cover a wider DMI table.
Makes sense. Will also update this one.
Kai-Heng
thanks,
Takashi