Re: [LKP] [lkp] [ALSA] ca53fbf3a6: WARNING: CPU: 0 PID: 151 at sound/hda/hdac_i915.c:129 pin2port+0x2a/0x40 [snd_hda_core]()

-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Tuesday, March 15, 2016 1:12 AM On Mon, 14 Mar 2016 16:30:22 +0100, Lin, Mengdong wrote: > > > -----Original Message----- > > From: Takashi Iwai [mailto:tiwai@suse.de] > > Sent: Monday, March 14, 2016 9:03 PM > > To: Yang, Libin > > Cc: kernel test robot; lkp(a)01.org; LKML; Wu, Fengguang; Lin, > > Mengdong > > Subject: Re: [lkp] [ALSA] ca53fbf3a6: WARNING: CPU: 0 PID: 151 at > > sound/hda/hdac_i915.c:129 pin2port+0x2a/0x40 [snd_hda_core]() > > > > On Mon, 14 Mar 2016 13:02:39 +0100, > > Yang, Libin wrote: > > > > > > Hi Takashi, > > > > > > > -----Original Message----- > > > > From: Takashi Iwai [mailto:tiwai@suse.de] > > > > Sent: Monday, March 14, 2016 3:23 PM > > > > To: kernel test robot > > > > Cc: lkp(a)01.org; LKML; Wu, Fengguang; Yang, Libin; Lin, Mengdong > > > > Subject: Re: [lkp] [ALSA] ca53fbf3a6: WARNING: CPU: 0 PID: 151 > > > > at > > > > sound/hda/hdac_i915.c:129 pin2port+0x2a/0x40 [snd_hda_core]() > > > > > > > > On Mon, 14 Mar 2016 01:50:45 +0100, kernel test robot wrote: > > > > > > > > > > FYI, we noticed the below changes on > > > > > > > > > > https://github.com/0day-ci/linux > > > > > Takashi-Iwai/ALSA-hda-Add-a-sanity- > > > > check-of-pin-port-mapping-on-i915-HDMI-DP/20160310-225740 > > > > > commit ca53fbf3a609b6831222078af9ddbecbf76fddce ("ALSA: hda - > > > > Add a sanity check of pin / port mapping on i915 HDMI/DP") > > > > > > > > > > > > > > > [ 14.546058] snd_hda_intel 0000:00:1b.0: bound 0000:00:02.0 > > (ops > > > > i915_audio_component_bind_ops [i915]) > > > > > [ 14.549740] fbcon: inteldrmfb (fb0) is primary device > > > > > [ 14.553691] ------------[ cut here ]------------ > > > > > [ 14.553707] WARNING: CPU: 0 PID: 151 at > > > > sound/hda/hdac_i915.c:129 pin2port+0x2a/0x40 [snd_hda_core]() > > > > > > > > Does your tree contain the commit > > > > 2f791908a70e95768596f5bb9e6de4f441d7bf13 > > > > drm/i915: Fix bogus dig_port_map[] assignment for pre-HSW ? > > > > > > > > The commit above should cover it even for HSW. > > > > > > > > If it's already included, then it's really a bug, and the > > > > warning is exactly for catching such a bug. The HD-audio driver > > > > expects that the valid audio ports are only from port B to port > > > > D while i915 driver assigns a different one. I suspect that the > > > > current assumption is too naive and broken for SKL and later in this regard. > > > > > > > > Libin, Mengdong, could you check whether the audio port mapping > > > > rule is still valid? At least, a wrong port-A mapping could be > > > > reproduced even on a HSW laptop with DP-MST dock when I boot > > without > > > > eDP (e.g. video=eDP-1:d option). > > > > > > We checked with HW before, and the mapping should be right. > > > What's the problem now? I will check with our HW and gfx team. > > > > One problem I've heard is that port-A is reported from i915 ELD notifier. > > This happens when you disable eDP and use DP-MST on a HSW machine. > > Then port A DDI is also used for the DP-MST, and when it's plugged, > > it passes > > port=0 to the notifier. > > Hi Takashi, > > Could you or someone provide the output of intel_audio_dump when the error happens? > This can help us to check the pipe:port connections in GPU from the display register values. > > For Haswell and later platforms, port A (DDI A) is only used for eDP, not for DP or HDMI. So I feel the DP-MST dock should not bridge port A to external monitors and so port A should not be reported by the ELD notifier. > Maybe the port mapping has bug since i915 support for DP MST is still ongoing. Below are four outputs with 4.5-final kernel:

Normal boot * intel-audio-laptop-normal DP monitor connected to built-in DP port

* intel-audio-dock-normal DP monitor connected to dock DP port

Boot with video=eDP-1:d option * intel-audio-laptop-noedp DP monitor connected to built-in DP port

* intel-audio-dock-noedp DP monitor connected to dock DP port

I didn't check whether *this* kernel really caused the issue. But, at least, the last case (intel-audio-dock-noedp) triggered eld notifier with port=0 in the past with 4.5-rc7.