https://bugs.freedesktop.org/show_bug.cgi?id=99881 --- Comment #30 from Matthew Fox --- Just to confirm, the freezes and hard lockups still occur and the corresponding messages in dmesg which I also attached. This may be more sound related but I previously found in the kernel source (file http://lxr.free-electrons.com/source/sound/pci/hda/hda_intel.c?v=4.8): 1182 static int register_vga_switcheroo(struct azx *chip) 1183 { 1184 struct hda_intel *hda = container_of(chip, struct hda_intel, chip); 1185 int err; 1186 1187 if (!hda->use_vga_switcheroo) 1188 return 0; 1189 /* FIXME: currently only handling DIS controller 1190 * is there any machine with two switchable HDMI audio controllers? 1191 */ 1192 err = vga_switcheroo_register_audio_client(chip->pci, &azx_vs_ops, 1193 VGA_SWITCHEROO_DIS); 1194 if (err < 0) 1195 return err; 1196 hda->vga_switcheroo_registered = 1; 1197 1198 /* register as an optimus hdmi audio power domain */ 1199 vga_switcheroo_init_domain_pm_optimus_hdmi_audio(chip->card->dev, 1200 &hda->hdmi_pm_domain); 1201 return 0; 1202 } In dmesg, these lines always appear along with the gpu init lines: snd_hda_intel 0000:02:00.1: Enabling via vga_switcheroo snd_hda_intel 0000:02:00.1: CORB reset timeout#2, CORBRP = 65535 snd_hda_intel 0000:02:00.1: Disabling via vga_switcheroo snd_hda_intel 0000:02:00.1: Cannot lock devices! 'CORB reset timeout#2, CORBRP = 65535' appears red in dmesg and 'Cannot lock devices!' appears white in dmesg. 0000:02:00.1 is the Discrete audio attached to the discrete GPU (the discrete GPU is 02:00.0) >From lspci, there's another audio device: 00:14.2 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 Azalia (Intel HDA) [1002:4383] (rev 40) Now in the function above, it says '...is there any machine with two switchable HDMI audio controllers?' - I wonder if that's the case here? Which might be causing problems and the associated sound messages in dmesg? -- You are receiving this mail because: You are the assignee for the bug.