[Intel-gfx] Warning: Broadwell/i915: Unclaimed register detected before reading register 0x130040

[Jochen Betz]

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This is my first post to a mailing list... I hope it works out. I
couldn't find more details on how to do it.

I'm getting the same error message as described in the original post,
expect for the register (address?). As proposed in the dmesg output I
booted with i915.mmio_debug=1 to get more info. This is what i get:


[  272.898632] WARNING: CPU: 3 PID: 0 at
/build/linux-Xbe5gu/linux-4.0.2/drivers/gpu/drm/i915/intel_uncore.c:551
hsw_unclaimed_reg_debug+0x6d/0x80
[i915]()
[  272.898634] Unclaimed register detected after reading register 0x44200
[  272.898635] Modules linked in: ctr ccm binfmt_misc
cpufreq_userspace cpufreq_stats cpufreq_powersave cpufreq_conservative
nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc
algif_skcipher af_alg nls_utf8 nls_cp437 vfat fat uvcvideo
videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev
media btusb bluetooth hid_generic usbhid arc4 iwlmvm mac80211 nvram
iwlwifi rtsx_pci_ms msr memstick rtsx_pci_sdmmc cfg80211 dell_laptop
joydev iTCO_wdt iTCO_vendor_support rfkill rtsx_pci snd_hda_codec_hdmi
dcdbas dell_wmi hid_multitouch sparse_keymap x86_pkg_temp_thermal
intel_powerclamp intel_rapl iosf_mbi coretemp kvm_intel kvm
crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel
efi_pstore evdev psmouse xhci_pci ehci_pci xhci_hcd serio_raw pcspkr
ehci_hcd efivars usbcore
[  272.898664]  sg usb_common mei_me lpc_ich mei shpchp
snd_hda_codec_realtek mfd_core i2c_i801 snd_hda_codec_generic i915
snd_hda_intel snd_hda_controller snd_hda_codec drm_kms_helper
snd_hwdep snd_pcm snd_timer drm i2c_hid snd i2c_algo_bit soundcore hid
wmi battery int3403_thermal sdhci_acpi sdhci video dw_dmac mmc_core
dw_dmac_core snd_soc_sst_acpi i2c_designware_platform
i2c_designware_core i2c_core processor_thermal_device int3402_thermal
int340x_thermal_zone int3400_thermal button acpi_thermal_rel
intel_smartconnect ac acpi_pad processor fuse parport_pc ppdev lp
parport autofs4 ext4 crc16 mbcache jbd2 dm_crypt dm_mod sd_mod ahci
libahci aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper
cryptd libata scsi_mod thermal fan thermal_sys
[  272.898701] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G        W
 4.0.0-1-amd64 #1 Debian 4.0.2-1
[  272.898702] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A04
05/15/2015
[  272.898704]  0000000000000000 ffffffffa05445b8 ffffffff8155df6b
ffff88021f583dd8
[  272.898706]  ffffffff8106ce91 ffff880214840000 0000000000044200
ffff880214840068
[  272.898708]  0000000080000002 0000000000000046 ffffffff8106cf0a
ffffffffa0544580
[  272.898711] Call Trace:
[  272.898712]  <IRQ>  [<ffffffff8155df6b>] ? dump_stack+0x40/0x50
[  272.898721]  [<ffffffff8106ce91>] ? warn_slowpath_common+0x81/0xb0
[  272.898723]  [<ffffffff8106cf0a>] ? warn_slowpath_fmt+0x4a/0x50
[  272.898737]  [<ffffffffa04cb2bd>] ?
hsw_unclaimed_reg_debug+0x6d/0x80 [i915]
[  272.898747]  [<ffffffffa04cd8a9>] ? gen6_read32+0xc9/0x190 [i915]
[  272.898751]  [<ffffffff81047f1e>] ? lapic_next_deadline+0x2e/0x40
[  272.898762]  [<ffffffffa04bb887>] ? gen8_irq_handler+0x47/0x490 [i915]
[  272.898765]  [<ffffffff810be885>] ? handle_irq_event_percpu+0x75/0x190
[  272.898767]  [<ffffffff810be9de>] ? handle_irq_event+0x3e/0x60
[  272.898769]  [<ffffffff810c1ae1>] ? handle_edge_irq+0x81/0x140
[  272.898773]  [<ffffffff8101649d>] ? handle_irq+0x1d/0x30
[  272.898776]  [<ffffffff815670a6>] ? do_IRQ+0x46/0xe0
[  272.898778]  [<ffffffff81564ead>] ? common_interrupt+0x6d/0x6d
[  272.898779]  <EOI>  [<ffffffff81432f51>] ?
cpuidle_enter_state+0x61/0x160
[  272.898785]  [<ffffffff81432f3e>] ? cpuidle_enter_state+0x4e/0x160
[  272.898787]  [<ffffffff810aa57f>] ? cpu_startup_entry+0x36f/0x420
[  272.898790]  [<ffffffff810dc910>] ? tick_check_new_device+0xe0/0x110
[  272.898792]  [<ffffffff810466f9>] ? start_secondary+0x199/0x1c0
[  272.898794] ---[ end trace 1676def838cce61c ]---


For me this is 100% reproducible. I just started to write a small demo
in using opengl. And when ever I launch my little up to draw some
stuff it's flooding the kernel buffer.

My machine is a XPS13 (2015) with an i5 and the non-touch FullHD display.

I'm using the following kernel

uname -a
Linux machiavelli 4.0.0-1-amd64 #1 SMP Debian 4.0.2-1 (2015-05-11)
x86_64 GNU/Linux


For me even worse is, that from time to time the complete machine
freezes when I run my application. It never happens otherwise. So my
speculation is, that there is a strong link between the driver error
and the usage of opengl in my application.

If you need more information, plz let me know.



- -- 
Dipl.-Ing. Jochen Betz
jochen.betz at gmx.net
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