[drm:hsw_unclaimed_reg_detect] ERROR Unclaimed register detected. Please use the i915.mmio_debug=1 to debug this problem.

Fri Dec 12 04:31:54 PST 2014

A syslog entry of a  newly installed ThinkPad T440s advices me :

Dec 12 00:17:59 t44 kernel: [drm:hsw_unclaimed_reg_detect] *ERROR* Unclaimed register detected. Please use the i915.mmio_debug=1 to debug this problem.

after ei s2disk'ed and resumed it.

So I did it and recompiled the kernel with CONFIG_MMIOTRACE=y,
s2disk'ed the sytem again and got this (it is a hardened 64 bit Gentoo kernel):

Dec 12 13:22:12 t44 kernel: ACPI: Preparing to enter system sleep state S4
Dec 12 13:22:12 t44 kernel: PM: Saving platform NVS memory
Dec 12 13:22:12 t44 kernel: Disabling non-boot CPUs ...
Dec 12 13:22:12 t44 kernel: intel_pstate CPU 1 exiting
Dec 12 13:22:12 t44 kernel: kvm: disabling virtualization on CPU1
Dec 12 13:22:12 t44 kernel: smpboot: CPU 1 is now offline
Dec 12 13:22:12 t44 kernel: intel_pstate CPU 2 exiting
Dec 12 13:22:12 t44 kernel: kvm: disabling virtualization on CPU2
Dec 12 13:22:12 t44 kernel: smpboot: CPU 2 is now offline
Dec 12 13:22:12 t44 kernel: intel_pstate CPU 3 exiting
Dec 12 13:22:12 t44 kernel: kvm: disabling virtualization on CPU3
Dec 12 13:22:12 t44 kernel: smpboot: CPU 3 is now offline
Dec 12 13:22:12 t44 kernel: PM: Creating hibernation image:
Dec 12 13:22:13 t44 kernel: PM: Need to copy 135989 pages
Dec 12 13:22:12 t44 kernel: PM: Restoring platform NVS memory
Dec 12 13:22:12 t44 kernel: Enabling non-boot CPUs ...
Dec 12 13:22:12 t44 kernel: x86: Booting SMP configuration:
Dec 12 13:22:12 t44 kernel: smpboot: Booting Node 0 Processor 1 APIC 0x1
Dec 12 13:22:12 t44 kernel: PAX: PCID detected
Dec 12 13:22:12 t44 kernel: PAX: strong UDEREF enabled
Dec 12 13:22:12 t44 kernel: PAX: INVPCID detected
Dec 12 13:22:12 t44 kernel: kvm: enabling virtualization on CPU1
Dec 12 13:22:12 t44 kernel: CPU1 is up
Dec 12 13:22:12 t44 kernel: smpboot: Booting Node 0 Processor 2 APIC 0x2
Dec 12 13:22:13 t44 kernel: PAX: PCID detected
Dec 12 13:22:13 t44 kernel: PAX: strong UDEREF enabled
Dec 12 13:22:13 t44 kernel: PAX: INVPCID detected
Dec 12 13:22:13 t44 kernel: kvm: enabling virtualization on CPU2
Dec 12 13:22:13 t44 kernel: CPU2 is up
Dec 12 13:22:13 t44 kernel: smpboot: Booting Node 0 Processor 3 APIC 0x3
Dec 12 13:22:13 t44 kernel: PAX: PCID detected
Dec 12 13:22:13 t44 kernel: PAX: strong UDEREF enabled
Dec 12 13:22:13 t44 kernel: PAX: INVPCID detected
Dec 12 13:22:13 t44 kernel: kvm: enabling virtualization on CPU3
Dec 12 13:22:13 t44 kernel: CPU3 is up
Dec 12 13:22:13 t44 kernel: ACPI: Waking up from system sleep state S4
Dec 12 13:22:13 t44 kernel: thinkpad_acpi: EC reports that Thermal Table has changed
Dec 12 13:22:13 t44 kernel: acpi LNXPOWER:02: Turning OFF
Dec 12 13:22:13 t44 kernel: PM: noirq restore of devices complete after 11.039 msecs
Dec 12 13:22:13 t44 kernel: ------------[ cut here ]------------
Dec 12 13:22:13 t44 kernel: WARNING: CPU: 3 PID: 2750 at drivers/gpu/drm/i915/intel_uncore.c:528 hsw_unclaimed_reg_debug.isra.11+0x8d/0xa0 [i915]()
Dec 12 13:22:13 t44 kernel: Unclaimed register detected before reading register 0x130040
Dec 12 13:22:13 t44 kernel: Modules linked in: ctr ccm ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_multiport nf_log_ipv4 nf_log_common xt_LOG xt_limit ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 xt_tcpudp xt_recent xt_conntrack iptable_filter ip_tables x_tables nf_conntrack_ftp nf_conntrack af_packet hid_generic hid_cherry usbhid hid uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev arc4 snd_hda_codec_generic x86_pkg_temp_thermal coretemp kvm_intel evdev iTCO_wdt kvm iwlmvm aesni_intel aes_x86_64 mac80211 glue_helper lrw gf128mul ablk_helper cryptd psmouse iwlwifi atkbd cfg80211 thermal wmi i915 cfbfillrect fbcon thinkpad_acpi cfbimgblt bitblit softcursor nvram font i2c_algo_bit rfkill cfbcopyarea tpm_tis tpm battery ac drm_kms_helper snd_hda_intel video snd_hda_controller drm
Dec 12 13:22:13 t44 kernel:  intel_gtt e1000e i2c_i801 agpgart ehci_pci xhci_hcd snd_hda_codec ptp ehci_hcd button snd_pcm fb i2c_core fbdev pps_core processor lpc_ich snd_timer usbcore mfd_core snd thermal_sys usb_common soundcore hwmon [last unloaded: microcode]
Dec 12 13:22:13 t44 kernel: CPU: 3 PID: 2750 Comm: kworker/u8:6 Not tainted 3.17.6-hardened #7
Dec 12 13:22:13 t44 kernel: Hardware name: LENOVO 20AQCTO1WW/20AQCTO1WW, BIOS GJET80WW (2.30 ) 10/20/2014
Dec 12 13:22:13 t44 kernel: Workqueue: events_unbound ffffffff81077030
Dec 12 13:22:13 t44 kernel:  ffffffff818147c7 0000000000000000 0000000000000009 ffffc9002a6cbb68
Dec 12 13:22:13 t44 kernel:  ffffffff815092b5 ffffc9002a6cbbb0 ffffc9002a6cbba0 ffffffff810527bd
Dec 12 13:22:13 t44 kernel:  ffffffffc0614c50 0000000000000210 ffffffffc0614c78 ffff88032cc80060
Dec 12 13:22:13 t44 kernel: Call Trace:
Dec 12 13:22:13 t44 kernel:  [<ffffffff815092b5>] dump_stack+0x45/0x5c
Dec 12 13:22:13 t44 kernel:  [<ffffffff810527bd>] warn_slowpath_common+0x7d/0xa0
Dec 12 13:22:13 t44 kernel:  [<ffffffffc0614c50>] ? i915_ioctls+0x4db0/0x16b28 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc0614c78>] ? i915_ioctls+0x4dd8/0x16b28 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffff81052840>] warn_slowpath_fmt+0x60/0x80
Dec 12 13:22:13 t44 kernel:  [<ffffffffc0614c78>] ? i915_ioctls+0x4dd8/0x16b28 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffff8144d384>] ? pci_conf1_write+0xc4/0x110
Dec 12 13:22:13 t44 kernel:  [<ffffffffc061f7a1>] ? i915_ioctls+0xf901/0x16b28 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc061f78e>] ? i915_ioctls+0xf8ee/0x16b28 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05a2e7d>] hsw_unclaimed_reg_debug.isra.11+0x8d/0xa0 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05a5dbe>] gen6_read32+0x5e/0x170 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05584b0>] ? i915_resume_early+0x50/0x50 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05bbcac>] hsw_disable_pc8+0x4c/0x3f0 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05584b0>] ? i915_resume_early+0x50/0x50 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc0558300>] i915_drm_thaw_early+0x60/0x70 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05584a3>] i915_resume_early+0x43/0x50 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05584c9>] i915_pm_resume_early+0x19/0x30 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffff813e1975>] dpm_run_callback+0x45/0x130
Dec 12 13:22:13 t44 kernel:  [<ffffffffc05584b0>] ? i915_resume_early+0x50/0x50 [i915]
Dec 12 13:22:13 t44 kernel:  [<ffffffff813e1c9a>] device_resume_early+0x9a/0x160
Dec 12 13:22:13 t44 kernel:  [<ffffffff813e1d80>] async_resume_early+0x20/0x50
Dec 12 13:22:13 t44 kernel:  [<ffffffff81077076>] async_run_entry_fn+0x46/0x140
Dec 12 13:22:13 t44 kernel:  [<ffffffff8106e1cd>] process_one_work+0x14d/0x420
Dec 12 13:22:13 t44 kernel:  [<ffffffff8106f39d>] worker_thread+0x12d/0x4c0
Dec 12 13:22:13 t44 kernel:  [<ffffffff8106f270>] ? destroy_workqueue+0x1e0/0x1e0
Dec 12 13:22:13 t44 kernel:  [<ffffffff810740c0>] kthread+0xf0/0x110
Dec 12 13:22:13 t44 kernel:  [<ffffffff81073fd0>] ? kthread_create_on_node+0x190/0x190
Dec 12 13:22:13 t44 kernel:  [<ffffffff81510944>] ret_from_fork+0x74/0xa0
Dec 12 13:22:13 t44 kernel:  [<ffffffff81073fd0>] ? kthread_create_on_node+0x190/0x190
Dec 12 13:22:13 t44 kernel: ---[ end trace 257ccda62b742443 ]---
Dec 12 13:22:13 t44 kernel: PM: early restore of devices complete after 6.122 msecs
Dec 12 13:22:13 t44 kernel: usb usb1: root hub lost power or was reset
Dec 12 13:22:13 t44 kernel: usb usb2: root hub lost power or was reset
Dec 12 13:22:13 t44 kernel: snd_hda_intel 0000:00:1b.0: irq 43 for MSI/MSI-X
Dec 12 13:22:13 t44 kernel: xhci_hcd 0000:00:14.0: irq 44 for MSI/MSI-X
Dec 12 13:22:13 t44 kernel: usb usb3: root hub lost power or was reset
Dec 12 13:22:13 t44 kernel: sd 0:0:0:0: [sda] Starting disk
Dec 12 13:22:13 t44 kernel: rtc_cmos 00:02: System wakeup disabled by ACPI
Dec 12 13:22:13 t44 kernel: ehci-pci 0000:00:1d.0: cache line size of 64 is not supported
Dec 12 13:22:13 t44 kernel: iwlwifi 0000:03:00.0: RF_KILL bit toggled to enable radio.
Dec 12 13:22:13 t44 kernel: e1000e 0000:00:19.0: irq 46 for MSI/MSI-X

-- 
Toralf
pgp key: 7B1A 07F4 EC82 0F90 D4C2  8936 872A E508 0076 E94E