Hi! While 5.5.x works fine, mainline as of ac309e7744be (v5.6-rc6+) causes me some sound-related trouble: after boot, the sound works fine -- but once I suspend and resume my broadwell-based XPS13, I need to switch to headphone and back to speaker to hear something. But what I hear isn't music but garbled output. A few dmesg snippets from v5.6-rc6-9-gac309e7744be which might be of interest. I've highlighted the lines differing from v.5.5.x which might be of special interest: ... snd_hda_intel 0000:00:03.0: enabling device (0000 -> 0002) usbcore: registered new interface driver snd-usb-audio snd_hda_intel 0000:00:03.0: bound 0000:00:02.0 (ops i915_audio_component_bind_ops) input: HDA Intel HDMI HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:03.0/sound/card0/input13 input: HDA Intel HDMI HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:03.0/sound/card0/input14 input: HDA Intel HDMI HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:03.0/sound/card0/input15 input: HDA Intel HDMI HDMI/DP,pcm=9 as /devices/pci0000:00/0000:00:03.0/sound/card0/input16 input: HDA Intel HDMI HDMI/DP,pcm=10 as /devices/pci0000:00/0000:00:03.0/sound/card0/input17 Console: switching to colour frame buffer device 240x67 !!! sst-acpi INT3438:00: WARN: Device release is not defined so it is not safe to unbind this driver while in use i915 0000:00:02.0: fb0: i915drmfb frame buffer device sst-acpi INT3438:00: DesignWare DMA Controller, 8 channels psmouse serio1: synaptics: Unable to query device: -5 haswell-pcm-audio haswell-pcm-audio: Direct firmware load for intel/IntcPP01.bin failed with error -2 haswell-pcm-audio haswell-pcm-audio: fw image intel/IntcPP01.bin not available(-2) haswell-pcm-audio haswell-pcm-audio: FW loaded, mailbox readback FW info: type 01, - version: 00.00, build 77, source commit id: 876ac6906f31a43b6772b23c7c983ce9dcb18a19 rt286 i2c-INT343A:00: ASoC: sink widget DMIC1 overwritten rt286 i2c-INT343A:00: ASoC: source widget DMIC1 overwritten broadwell-audio broadwell-audio: snd-soc-dummy-dai <-> System Pin mapping ok broadwell-audio broadwell-audio: snd-soc-dummy-dai <-> Offload0 Pin mapping ok broadwell-audio broadwell-audio: snd-soc-dummy-dai <-> Offload1 Pin mapping ok broadwell-audio broadwell-audio: snd-soc-dummy-dai <-> Loopback Pin mapping ok broadwell-audio broadwell-audio: rt286-aif1 <-> snd-soc-dummy-dai mapping ok input: broadwell-rt286 Headset as /devices/pci0000:00/INT3438:00/broadwell-audio/sound/card1/input18 ... ALSA device list: #0: HDA Intel HDMI at 0xf7218000 irq 48 #1: DellInc.-XPS139343--0TM99H ... !!! haswell-pcm-audio haswell-pcm-audio: warning: stream is NULL, no stream to reset, ignore it. !!! haswell-pcm-audio haswell-pcm-audio: warning: stream is NULL, no stream to free, ignore it. (these last two messages already are printed a couple of time after boot, and then again during a suspend/resume cycle. On v.5.5.y, there are similar messages "no context buffer need to restore!"). Everything is built-in, no modules are loaded. Unfortunately, I cannot bisect this issue easily -- i915 was broken for quite some time on this system[*], prohibiting boot... Thanks for taking a look at this issue! Dominik [*] https://gitlab.freedesktop.org/drm/intel/issues/1151