drm/i915: Lock mode_config.mutex in intel_display_resume.
Unfortunately i915 is still not fully atomic, and expects mode_config.mutex
to be held during modeset until we finally fix it.
This fixes the following WARN when resuming:
[ 425.208983] ------------[ cut here ]------------
[ 425.208990] WARNING: CPU: 0 PID: 6828 at drivers/gpu/drm/drm_edid.c:3555 drm_select_eld+0xa5/0xd0()
[ 425.209015] Modules linked in: pl2303 usbserial snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic intel_powerclamp coretemp i915 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_intel snd_hda_codec snd_hwdep lpc_ich snd_hda_core snd_pcm i2c_hid i2c_designware_platform i2c_designware_core r8169 mii sdhci_acpi sdhci mmc_core
[ 425.209018] CPU: 0 PID: 6828 Comm: kworker/u4:5 Tainted: G U W 4.5.0-rc4-gfxbench+ #1
[ 425.209020] Hardware name: \xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff \xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff\xffffffff/DN2820FYK, BIOS FYBYT10H.86A.0038.2014.0717.1455 07/17/2014
[ 425.209027] Workqueue: events_unbound async_run_entry_fn
[ 425.209032]
0000000000000000 ffff880072433958 ffffffff813f6b05 0000000000000000
[ 425.209036]
ffffffff81aaef2d ffff880072433990 ffffffff81078291 ffff880036b933d8
[ 425.209039]
ffff88006d528000 ffff88006d52b3d8 ffff88006d52b3d8 ffff88007315b6f8
[ 425.209040] Call Trace:
[ 425.209045] [<
ffffffff813f6b05>] dump_stack+0x67/0x92
[ 425.209049] [<
ffffffff81078291>] warn_slowpath_common+0x81/0xc0
[ 425.209052] [<
ffffffff81078385>] warn_slowpath_null+0x15/0x20
[ 425.209054] [<
ffffffff8151e195>] drm_select_eld+0xa5/0xd0
[ 425.209101] [<
ffffffffa01f34f4>] intel_audio_codec_enable+0x44/0x160 [i915]
[ 425.209135] [<
ffffffffa023eac7>] intel_enable_hdmi_audio+0x87/0x90 [i915]
[ 425.209169] [<
ffffffffa023eb5a>] g4x_enable_hdmi+0x8a/0xa0 [i915]
[ 425.209202] [<
ffffffffa023f41b>] vlv_hdmi_pre_enable+0x1cb/0x240 [i915]
[ 425.209236] [<
ffffffffa020edcf>] valleyview_crtc_enable+0x10f/0x290 [i915]
[ 425.209270] [<
ffffffffa020ba49>] intel_atomic_commit+0x769/0x17a0 [i915]
[ 425.209274] [<
ffffffff81526ad5>] ? drm_atomic_check_only+0x145/0x660
[ 425.209276] [<
ffffffff81527022>] drm_atomic_commit+0x32/0x50
[ 425.209310] [<
ffffffffa0215fa0>] intel_display_resume+0xa0/0x130 [i915]
[ 425.209338] [<
ffffffffa018c1bb>] i915_drm_resume+0xcb/0x160 [i915]
[ 425.209366] [<
ffffffffa018c272>] i915_pm_resume+0x22/0x30 [i915]
[ 425.209370] [<
ffffffff8143d91e>] pci_pm_resume+0x6e/0xe0
[ 425.209373] [<
ffffffff8143d8b0>] ? pci_pm_resume_noirq+0xa0/0xa0
[ 425.209375] [<
ffffffff815409ae>] dpm_run_callback+0x6e/0x280
[ 425.209378] [<
ffffffff815410b2>] device_resume+0x92/0x250
[ 425.209380] [<
ffffffff81541288>] async_resume+0x18/0x40
[ 425.209382] [<
ffffffff8109c7a5>] async_run_entry_fn+0x45/0x140
[ 425.209386] [<
ffffffff81093293>] process_one_work+0x1e3/0x620
[ 425.209388] [<
ffffffff810931f7>] ? process_one_work+0x147/0x620
[ 425.209391] [<
ffffffff81093719>] worker_thread+0x49/0x490
[ 425.209393] [<
ffffffff810936d0>] ? process_one_work+0x620/0x620
[ 425.209396] [<
ffffffff81099e0a>] kthread+0xea/0x100
[ 425.209400] [<
ffffffff81099d20>] ? kthread_create_on_node+0x1f0/0x1f0
[ 425.209404] [<
ffffffff817ba03f>] ret_from_fork+0x3f/0x70
[ 425.209407] [<
ffffffff81099d20>] ? kthread_create_on_node+0x1f0/0x1f0
[ 425.209409] ---[ end trace
d1b247107f34a8b2 ]---
Fixes: e2c8b8701e2d ("drm/i915: Use atomic helpers for suspend, v2.")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455632862-18557-1-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>