Warning on resume

[Stephen Hemminger]

I got this on my desktop (Haswell) box when resuming from suspend
with Debian testing kernel (3.13).


[147765.739493] ------------[ cut here ]------------
[147765.739501] WARNING: CPU: 1 PID: 29426 at /build/linux-oxWk_8/linux-3.13.7/drivers/gpu/drm/i915/intel_ddi.c:763 intel_ddi_pll_mode_set+0x218/0x8e0 [i915]()
[147765.739502] WRPLL already enabled
[147765.739513] Modules linked in: nls_utf8 nls_cp437 vfat fat ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle xt_tcpudp tun bridge stp llc usb_storage ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables bnep rfcomm bluetooth rfkill cpufreq_conservative cpufreq_stats cpufreq_userspace cpufreq_powersave binfmt_misc sch_fq_codel fuse loop parport_pc ppdev lp parport snd_hda_codec_hdmi snd_hda_codec_realtek x86_pkg_temp_thermal intel_powerclamp iTCO_wdt coretemp iTCO_vendor_support kvm_intel kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel evdev aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper snd_seq_midi snd_hda_intel snd_seq_midi_event cryptd snd_hda_codec psmouse snd_rawmidi serio_raw snd_hwdep snd_pcm_oss snd_mixer_oss lpc_ich i915 mfd_core snd_seq snd_pcm snd_seq_device snd_page_alloc i2c_i801 snd_timer drm_kms_helper snd drm mei_me video mei soundcore processor button ext4 crc16 mbcache jbd2 btrfs xor raid6_pq crc32c libcrc32c dm_mod sg sd_mod sr_mod crc_t10dif cdrom crct10dif_common hid_generic hid_belkin usbhid hid ahci libahci firewire_ohci libata scsi_mod firewire_core crc_itu_t igb ehci_pci xhci_hcd i2c_algo_bit ehci_hcd e1000e i2c_core fan usbcore thermal usb_common thermal_sys ixgbe dca ptp pps_core mdio
[147765.739526] CPU: 1 PID: 29426 Comm: kworker/u16:29 Tainted: G        W    3.13-1-amd64 #1 Debian 3.13.7-1
[147765.739526] Hardware name: Supermicro X10SAE/X10SAE, BIOS 1.1a 01/03/2014
[147765.739528] Workqueue: events_unbound async_run_entry_fn
[147765.739530]  0000000000000009 ffffffff814a1327 ffff8802ae387a88 ffffffff8105ba72
[147765.739531]  ffff88040b23c000 ffff8802ae387ad8 0000000000000001 00000000000278d0
[147765.739532]  ffff880409928000 ffffffff8105bad7 ffffffffa0541431 ffff880400000018
[147765.739532] Call Trace:
[147765.739534]  [<ffffffff814a1327>] ? dump_stack+0x41/0x51
[147765.739535]  [<ffffffff8105ba72>] ? warn_slowpath_common+0x72/0x90
[147765.739536]  [<ffffffff8105bad7>] ? warn_slowpath_fmt+0x47/0x50
[147765.739542]  [<ffffffffa051d1a8>] ? gen6_read32+0x48/0x110 [i915]
[147765.739548]  [<ffffffffa04f52f8>] ? intel_ddi_pll_mode_set+0x218/0x8e0 [i915]
[147765.739554]  [<ffffffffa04b2b86>] ? ironlake_enable_vblank+0x26/0x80 [i915]
[147765.739560]  [<ffffffffa04e3ad6>] ? haswell_crtc_mode_set+0x36/0x480 [i915]
[147765.739566]  [<ffffffffa04e7186>] ? __intel_set_mode+0x646/0x1500 [i915]
[147765.739571]  [<ffffffffa051d1a8>] ? gen6_read32+0x48/0x110 [i915]
[147765.739577]  [<ffffffffa04ed559>] ? intel_modeset_setup_hw_state+0xb19/0xc20 [i915]
[147765.739581]  [<ffffffffa04ad2aa>] ? __i915_drm_thaw+0x14a/0x200 [i915]
[147765.739585]  [<ffffffffa04ad3b1>] ? i915_resume+0x51/0x70 [i915]
[147765.739587]  [<ffffffff812a1ad0>] ? pci_pm_thaw+0x90/0x90
[147765.739588]  [<ffffffff8135be1e>] ? dpm_run_callback+0x2e/0x70
[147765.739589]  [<ffffffff8135bf2c>] ? device_resume+0x8c/0x180
[147765.739591]  [<ffffffff8135c034>] ? async_resume+0x14/0x40
[147765.739592]  [<ffffffff8108131d>] ? async_run_entry_fn+0x2d/0x120
[147765.739593]  [<ffffffff81074c4d>] ? process_one_work+0x16d/0x420
[147765.739594]  [<ffffffff81075816>] ? worker_thread+0x116/0x3b0
[147765.739596]  [<ffffffff81075700>] ? rescuer_thread+0x330/0x330
[147765.739596]  [<ffffffff8107bb41>] ? kthread+0xc1/0xe0
[147765.739597]  [<ffffffff8107ba80>] ? kthread_create_on_node+0x180/0x180
[147765.739599]  [<ffffffff814ae44c>] ? ret_from_fork+0x7c/0xb0
[147765.739600]  [<ffffffff8107ba80>] ? kthread_create_on_node+0x180/0x180
[147765.739600] ---[ end trace f16ec95e5a50ba64 ]---