i915 producing warnings with kernel 3.11-rc5

i915 producing warnings with kernel 3.11-rc5

[Michael S. Tsirkin]

I see lots of warning like this with 3.11-rc5 on my thinkpad t40.

[197481.739272] [drm:intel_pipe_config_compare] *ERROR* mismatch in adjusted_mode.flags (expected 1, found 0)
[197481.739283] ------------[ cut here ]------------
[197481.739352] WARNING: CPU: 0 PID: 556 at drivers/gpu/drm/i915/intel_display.c:8286 check_crtc_state+0x5cf/0xa50 [i915]()
[197481.739355] pipe state doesn't match!
[197481.739358] Modules linked in: fuse ebtable_nat xt_CHECKSUM nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6table_mangle ip6t_REJECT nf_conntrack_ipv6 bridge nf_defrag_ipv6 stp llc iptable_nat nf_nat_ipv4 nf_nat be2iscsi iscsi_boot_sysfs iptable_mangle bnx2i nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack lockd nf_conntrack sunrpc cnic ebtable_filter uio cxgb4i cxgb4 ebtables ip6table_filter ip6_tables cxgb3i cxgb3 mdio libcxgbi ib_iser rdma_cm ib_addr iw_cm ib_cm ib_sa ib_mad ib_core iscsi_tcp libiscsi_tcp rfcomm libiscsi scsi_transport_iscsi bnep arc4 iwldvm mac80211 btusb snd_hda_codec_hdmi iwlwifi snd_hda_codec_conexant snd_hda_intel snd_hda_codec bluetooth vhost_net cfg80211 tun macvtap macvlan iTCO_wdt uvcvideo iTCO_vendor_support snd_usb_audio vhost snd_usbmidi_li
 b videobuf2_vmalloc
[197481.739440]  snd_hwdep kvm_intel videobuf2_memops videobuf2_core videodev snd_rawmidi thinkpad_acpi e1000e kvm snd_seq rfkill i2c_i801 snd_seq_device snd_pcm snd_page_alloc snd_timer pcspkr lpc_ich mfd_core snd ptp tpm_tis pps_core wmi soundcore tpm tpm_bios binfmt_misc uinput i915 firewire_ohci firewire_core crc_itu_t i2c_algo_bit drm_kms_helper sdhci_pci sdhci drm mmc_core i2c_core video
[197481.739492] CPU: 0 PID: 556 Comm: X Tainted: G        W    3.11.0-rc5-mst #253
[197481.739497] Hardware name: LENOVO 4243BQ9/4243BQ9, BIOS 8AET57WW (1.37 ) 04/05/2012
[197481.739501]  000000000000205e ffff88020be47828 ffffffff81672e9d ffff88020be47868
[197481.739509]  ffffffff8105c52c 0000000000000000 ffff88021270fc70 ffff88021241d000
[197481.739516]  0000000000000001 ffff88021270fc78 ffff88021270f800 ffff88020be47948
[197481.739523] Call Trace:
[197481.739537]  [<ffffffff81672e9d>] dump_stack+0x6a/0x7d
[197481.739547]  [<ffffffff8105c52c>] warn_slowpath_common+0x8c/0xc0
[197481.739555]  [<ffffffff8105c65e>] warn_slowpath_fmt+0x6e/0x70
[197481.739589]  [<ffffffffa00c9385>] ? i915_read32+0x75/0x130 [i915]
[197481.739617]  [<ffffffffa00c9385>] ? i915_read32+0x75/0x130 [i915]
[197481.739657]  [<ffffffffa0104315>] ? intel_lvds_get_config+0x45/0xb0 [i915]
[197481.739692]  [<ffffffffa00f377f>] check_crtc_state+0x5cf/0xa50 [i915]
[197481.739730]  [<ffffffffa00faa85>] intel_modeset_check_state+0x2e5/0x7c0 [i915]
[197481.739758]  [<ffffffffa00c8eeb>] ? i915_write32+0xdb/0x140 [i915]
[197481.739792]  [<ffffffffa0103f7c>] intel_crt_dpms+0x8c/0xd0 [i915]
[197481.739826]  [<ffffffffa0057643>] drm_mode_obj_set_property_ioctl+0x393/0x3b0 [drm]
[197481.739854]  [<ffffffffa0057692>] drm_mode_connector_property_set_ioctl+0x32/0x40 [drm]
[197481.739880]  [<ffffffffa004964a>] drm_ioctl+0x3da/0x660 [drm]
[197481.739893]  [<ffffffff81142695>] ? __free_pages+0x45/0x50
[197481.739923]  [<ffffffffa0057660>] ? drm_mode_obj_set_property_ioctl+0x3b0/0x3b0 [drm]
[197481.739933]  [<ffffffff8129ecda>] ? file_has_perm+0xaa/0xb0
[197481.739977]  [<ffffffffa0130b75>] i915_compat_ioctl+0x45/0x50 [i915]
[197481.739985]  [<ffffffff811ee9f6>] compat_sys_ioctl+0x106/0x13a0
[197481.739994]  [<ffffffff8119dce9>] ? file_sb_list_del+0x49/0x50
[197481.740001]  [<ffffffff8107bd35>] ? task_work_add+0x55/0x70
[197481.740008]  [<ffffffff8119de15>] ? fput+0x75/0xb0
[197481.740017]  [<ffffffff810e3c2b>] ? __audit_syscall_exit+0x23b/0x2e0
[197481.740027]  [<ffffffff8168221c>] sysenter_dispatch+0x7/0x21
[197481.740031] ---[ end trace 60b3bfa00b791b28 ]---


The graphics card is:
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core
Processor Family Integrated Graphics Controller (rev 09)

Anyone interested in debugging the source of these warnings?

-- 
MST