Linux 4.1 WARNING in drm_ioctl.c

[Daniel Vetter]

On Mon, Jun 22, 2015 at 04:04:20PM +0200, Fabio Coatti wrote:
> Hi All,
> 
> just compiled 4.1 and just got this warning, twice, in my dmesg:
> 
> 
> [lun giu 22 11:43:18 2015] ------------[ cut here ]------------
> [lun giu 22 11:43:18 2015] WARNING: CPU: 1 PID: 2184 at 
> drivers/gpu/drm/drm_ioctl.c:144 drm_setversion+0xe1/0x179()
> [lun giu 22 11:43:18 2015] No drm_driver.set_busid() implementation provided 
> by 0xffffffff81ec3980. Use drm_dev_set_unique() to set the unique name 
> explicitly.
> [lun giu 22 11:43:18 2015] Modules linked in:
> [lun giu 22 11:43:18 2015]  bnep algif_skcipher cdc_wdm cdc_acm uvcvideo 
> videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev btusb 
> btbcm btintel bluetooth hp_wmi sparse_keymap intel_rapl iosf_mbi 
> x86_pkg_temp_thermal intel_powerclamp snd_hda_codec_hdmi coretemp kvm_intel 
> kvm snd_hda_codec_generic crct10dif_pclmul crc32_pclmul snd_hda_intel iwldvm 
> snd_hda_controller snd_hda_codec snd_hwdep psmouse snd_hda_core iwlwifi 
> snd_pcm snd_timer snd soundcore wmi hp_accel(+) hp_wireless lis3lv02d 
> sch_fq_codel dm_zero dm_persistent_data dm_service_time dm_round_robin 
> dm_queue_length dm_multipath dm_delay virtio_pci virtio_blk virtio_balloon 
> virtio_ring virtio fuse overlay linear raid0 dm_raid dm_snapshot dm_bufio 
> dm_mirror dm_region_hash dm_log ohci_pci ohci_hcd uhci_hcd
> [lun giu 22 11:43:18 2015] CPU: 1 PID: 2184 Comm: X Tainted: G        W       
> 4.1.0 #1
> [lun giu 22 11:43:18 2015] Hardware name: Hewlett-Packard HP EliteBook Folio 
> 9470m/18DF, BIOS 68IBD Ver. F.40 02/01/2013
> [lun giu 22 11:43:18 2015]  0000000000000000 0000000000000009 ffffffff818d8bfd 
> ffff8800b226fd38
> [lun giu 22 11:43:18 2015]  ffffffff810c5426 ffff880235437240 ffffffff8152870c 
> ffff8800b2f16000
> [lun giu 22 11:43:18 2015]  ffff880234ffc000 ffff8800b226fdf0 ffff8800b2c8f300 
> 00000000c0106407
> [lun giu 22 11:43:18 2015] Call Trace:
> [lun giu 22 11:43:18 2015]  [<ffffffff818d8bfd>] ? dump_stack+0x47/0x67
> [lun giu 22 11:43:18 2015]  [<ffffffff810c5426>] ? 
> warn_slowpath_common+0x9d/0xb5
> [lun giu 22 11:43:18 2015]  [<ffffffff8152870c>] ? drm_setversion+0xe1/0x179
> [lun giu 22 11:43:18 2015]  [<ffffffff810c5488>] ? warn_slowpath_fmt+0x4a/0x4f
> [lun giu 22 11:43:18 2015]  [<ffffffff8152870c>] ? drm_setversion+0xe1/0x179
> [lun giu 22 11:43:18 2015]  [<ffffffff81528465>] ? drm_ioctl+0x376/0x3dd
> [lun giu 22 11:43:18 2015]  [<ffffffff8152862b>] ? drm_version+0x8d/0x8d
> [lun giu 22 11:43:18 2015]  [<ffffffff811ca766>] ? do_filp_open+0x30/0x74
> [lun giu 22 11:43:18 2015]  [<ffffffff811cc591>] ? do_vfs_ioctl+0x379/0x431
> [lun giu 22 11:43:18 2015]  [<ffffffff811d4784>] ? __fd_install+0x20/0x52
> [lun giu 22 11:43:18 2015]  [<ffffffff811bccab>] ? do_sys_open+0x1c0/0x1d2
> [lun giu 22 11:43:18 2015]  [<ffffffff811cc687>] ? SyS_ioctl+0x3e/0x5a
> [lun giu 22 11:43:18 2015]  [<ffffffff818e0d9b>] ? 
> system_call_fastpath+0x16/0x6e
> [lun giu 22 11:43:18 2015] ---[ end trace 46364eedd82ef148 ]---
> 
> It does not seems to affect normal behaviour, but maybe the report could be 
> interesting for maintainers.
> 
> Sorry if this has already been reported; if more information is needed just 
> let me know (please CC: me as I'm not subscribed to lists.)

Which drm driver are you using? I didn't spot anything in your module list
but might have missed it. Booting with drm.debug=0xe and grabbing dmesg
will tell us for sure.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch