Created attachment 125629 [details] dmesg from 4.8-rc1 with drm.debug=0xe I just tried the current 4.8-rc1 kernel and it results in blank displays and a traceback in the system log. 4.7 and earlier versions work fine. Hardware: Thinkpad L460 in UltraDock with 2 external screens (DVI+HDMI ) Software: Arch Linux with Kernel 4.8-rc1 Could be related to bug 97182.
I figured out that this is somehow related to DMC FW 1.23. When I boot 4.8-rc1 with the old v1.23 FW (required) the system crashes with a black screen and I am getting this (see attachment 125629 [details]): [ 12.705057] divide error: 0000 [#1] PREEMPT SMP [ 12.705091] Modules linked in: snd_hda_codec_realtek(+) snd_hda_codec_generic nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT nf_reject_ipv4 xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ip6table_filter iptable_filter ip6_tables snd_soc_skl snd_soc_skl_ipc snd_hda_ext_core snd_soc_sst_dsp snd_soc_sst_ipc snd_soc_sst_match snd_soc_core arc4 iTCO_wdt iTCO_vendor_support psmouse serio_raw atkbd libps2 iwlmvm intel_rapl x86_pkg_temp_thermal mac80211 intel_powerclamp efi_pstore coretemp snd_hda_intel kvm rtsx_pci_ms irqbypass snd_hda_codec iwlwifi i915 snd_hwdep memstick snd_hda_core efivars cfg80211 e1000e snd_pcm i2c_i801 i2c_smbus btusb snd_timer intel_gtt ptp pps_core i2c_algo_bit joydev shpchp btrtl thinkpad_acpi mousedev evdev nvram input_leds btbcm drm_kms_helper btintel wmi [ 12.705533] mac_hid snd bluetooth syscopyarea battery ac soundcore sysfillrect led_class i8042 sysimgblt fb_sys_fops serio drm video thermal crc16 rfkill intel_pch_thermal button tpm_tis tpm_tis_core tpm sch_fq_codel ip_tables x_tables btrfs xor raid6_pq algif_skcipher af_alg hid_logitech_hidpp hid_logitech_dj usbhid dm_crypt dm_mod rtsx_pci_sdmmc mmc_core crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel rtsx_pci sd_mod xhci_pci xhci_hcd hid_microsoft hid jitterentropy_rng sha256_ssse3 sha256_generic hmac drbg ansi_cprng [ 12.705840] CPU: 3 PID: 438 Comm: Xorg Not tainted 4.8.0-rc1-git+ #13 [ 12.705870] Hardware name: LENOVO 20FVS01500/20FVS01500, BIOS R08ET42W (1.16 ) 06/17/2016 [ 12.705907] task: ffff88042f128000 task.stack: ffff8804237a8000 [ 12.705935] RIP: 0010:[<ffffffffa061c839>] [<ffffffffa061c839>] skl_compute_wm+0x1d9/0x1200 [i915] [ 12.705996] RSP: 0018:ffff8804237abad0 EFLAGS: 00010206 [ 12.706022] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88042fc55000 [ 12.706054] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 12.706087] RBP: ffff8804237abba0 R08: 0000000000000001 R09: 000000000000037c [ 12.706120] R10: ffffffffa070be97 R11: 00000000ffffffff R12: ffff880428080000 [ 12.706153] R13: ffff880427ed7000 R14: ffff88042fc55000 R15: ffff88042fc53800 [ 12.706186] FS: 00007fa84b2e8940(0000) GS:ffff8804434c0000(0000) knlGS:0000000000000000 [ 12.706224] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 12.706251] CR2: 00007fa84b3b9000 CR3: 0000000423787000 CR4: 00000000003406e0 [ 12.706284] Stack: [ 12.706296] ffff880428080000 ffff880428080000 ffff88042376d320 0000000000000008 [ 12.706337] 0000000000000001 ffff88042fc53800 ffff88042fc55000 0000000000000000 [ 12.706378] ffff880428080000 ffff880427ed7000 ffff88042fc5527c ffffffffa0689d7d [ 12.706419] Call Trace: [ 12.706451] [<ffffffffa0689d7d>] ? intel_crtc_atomic_check+0x18d/0x220 [i915] [ 12.706501] [<ffffffffa068cb67>] intel_atomic_check+0x9e7/0x11c0 [i915] [ 12.706534] [<ffffffff81313aa3>] ? idr_alloc+0x83/0x100 [ 12.706566] [<ffffffffa02d73d7>] drm_atomic_check_only+0x187/0x610 [drm] [ 12.706602] [<ffffffffa02d8023>] ? drm_atomic_replace_property_blob_from_id.isra.7+0x53/0x90 [drm] [ 12.706647] [<ffffffffa02d7877>] drm_atomic_commit+0x17/0x60 [drm] [ 12.706680] [<ffffffffa04dec3c>] drm_atomic_helper_legacy_gamma_set+0x14c/0x1a0 [drm_kms_helper] [ 12.706689] [<ffffffffa067c5fb>] intel_atomic_legacy_gamma_set+0x1b/0xa0 [i915] [ 12.706689] [<ffffffffa02cb9f1>] drm_mode_gamma_set_ioctl+0x141/0x150 [drm] [ 12.706689] [<ffffffffa02bcd36>] drm_ioctl+0x2e6/0x4c0 [drm] [ 12.706689] [<ffffffffa02cb8b0>] ? drm_mode_connector_property_set_ioctl+0x60/0x60 [drm] [ 12.706689] [<ffffffff8121ecc4>] ? __vfs_write+0xe4/0x140 [ 12.706689] [<ffffffff81232682>] do_vfs_ioctl+0xa2/0x5d0 [ 12.706689] [<ffffffff810e6197>] ? percpu_up_read+0x17/0x40 [ 12.706689] [<ffffffff8123d697>] ? __fget+0x77/0xb0 [ 12.706689] [<ffffffff81232c29>] SyS_ioctl+0x79/0x90 [ 12.706689] [<ffffffff8163a9b2>] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 12.706689] Code: 19 c9 d3 e0 31 d2 48 8b 8d 60 ff ff ff 41 81 e1 80 01 00 00 83 e8 01 41 81 c1 fc 01 00 00 21 f8 89 c7 f3 0f b8 c7 90 41 0f af c1 <f7> f6 31 d2 89 c7 48 63 c3 48 8d 0c 81 48 89 45 c0 44 89 c8 f7 [ 12.706689] RIP [<ffffffffa061c839>] skl_compute_wm+0x1d9/0x1200 [i915] [ 12.706689] RSP <ffff8804237abad0> [ 12.716770] ---[ end trace 2cba5b21f2b23959 ]--- When I change the code in intel_csr.c to load DMC FW v1.26 the system boots fine, without any call traces.
Issue is fixed in 4.8-rc4 by 177d91aaea4bcafb29232336bafaa521b85286aa.
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