linux/drivers/gpu/drm
Rodrigo Vivi bc5f2ab11c drm/i915/skl: Don't call intel_prepare_ddi when encoder list isn't yet initialized.
In case something goes wrong with power well initialization we were calling
intel_prepare_ddi during boot while encoder list isnt't initilized.

[    9.618747] i915 0000:00:02.0: Invalid ROM contents
[    9.631446] [drm] failed to find VBIOS tables
[    9.720036] BUG: unable to handle kernel NULL pointer dereference at 00000000
00000058
[    9.721986] IP: [<ffffffffa014eb72>] ddi_get_encoder_port+0x82/0x190 [i915]
[    9.723736] PGD 0
[    9.724286] Oops: 0000 [#1] PREEMPT SMP
[    9.725386] Modules linked in: intel_powerclamp snd_hda_intel(+) coretemp crc
32c_intel snd_hda_codec snd_hda_core serio_raw snd_pcm snd_timer i915(+) parport
_pc parport pinctrl_sunrisepoint pinctrl_intel nfsd nfs_acl
[    9.730635] CPU: 0 PID: 497 Comm: systemd-udevd Not tainted 4.3.0-rc2-eywa-10
967-g72de2cfd-dirty #2
[    9.732785] Hardware name: Intel Corporation Cannonlake Client platform/Skyla
ke DT DDR4 RVP8, BIOS CNLSE2R1.R00.X021.B00.1508040310 08/04/2015
[    9.735785] task: ffff88008a704700 ti: ffff88016a1ac000 task.ti: ffff88016a1a
c000
[    9.737584] RIP: 0010:[<ffffffffa014eb72>]  [<ffffffffa014eb72>] ddi_get_enco
der_port+0x82/0x190 [i915]
[    9.739934] RSP: 0000:ffff88016a1af710  EFLAGS: 00010296
[    9.741184] RAX: 000000000000004e RBX: ffff88008a9edc98 RCX: 0000000000000001
[    9.742934] RDX: 000000000000004e RSI: ffffffff81fc1e82 RDI: 00000000ffffffff
[    9.744634] RBP: ffff88016a1af730 R08: 0000000000000000 R09: 0000000000000578
[    9.746333] R10: 0000000000001065 R11: 0000000000000578 R12: fffffffffffffff8
[    9.748033] R13: ffff88016a1af7a8 R14: ffff88016a1af794 R15: 0000000000000000
[    9.749733] FS:  00007eff2e1e07c0(0000) GS:ffff88016fc00000(0000) knlGS:00000
00000000000
[    9.751683] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    9.753083] CR2: 0000000000000058 CR3: 000000016922b000 CR4: 00000000003406f0
[    9.754782] Stack:
[    9.755332]  ffff88008a9edc98 ffff88008a9ed800 ffffffffa01d07b0 00000000fffb9
09e
[    9.757232]  ffff88016a1af7d8 ffffffffa0154ea7 0000000000000246 ffff88016a370
080
[    9.759182]  ffff88016a370080 ffff88008a9ed800 0000000000000246 ffff88008a9ed
c98
[    9.761132] Call Trace:
[    9.761782]  [<ffffffffa0154ea7>] intel_prepare_ddi+0x67/0x860 [i915]
[    9.763332]  [<ffffffff81a56996>] ? _raw_spin_unlock_irqrestore+0x26/0x40
[    9.765031]  [<ffffffffa00fad01>] ? gen9_read32+0x141/0x360 [i915]
[    9.766531]  [<ffffffffa00b43e1>] skl_set_power_well+0x431/0xa80 [i915]
[    9.768181]  [<ffffffffa00b4a63>] skl_power_well_enable+0x13/0x20 [i915]
[    9.769781]  [<ffffffffa00b2188>] intel_power_well_enable+0x28/0x50 [i915]
[    9.771481]  [<ffffffffa00b4d52>] intel_display_power_get+0x92/0xc0 [i915]
[    9.773180]  [<ffffffffa00b4fcb>] intel_display_set_init_power+0x3b/0x40 [i91
5]
[    9.774980]  [<ffffffffa00b5170>] intel_power_domains_init_hw+0x120/0x520 [i9
15]
[    9.776780]  [<ffffffffa0194c61>] i915_driver_load+0xb21/0xf40 [i915]

So let's protect this case.

My first attempt was to remove the intel_prepare_ddi, but Daniel had pointed out
this is really needed to restore those registers values. And Imre pointed out
that this case was without the flag protection and this was actually where things
were going bad. So I've just checked and this indeed solves my issue.

The regressing intel_prepare_ddi call was added in

commit 1d2b9526a7
Author: Damien Lespiau <damien.lespiau@intel.com>
Date:   Fri Mar 6 18:50:53 2015 +0000

    drm/i915/skl: Restore the DDI translation tables when enabling PW1

Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
[Jani: regression reference]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2015-09-28 11:05:13 +03:00
..
amd drm/amdgpu: Sprinkle drm_modeset_lock_all to appease locking checks 2015-09-23 17:23:46 -04:00
armada drm/armada: Use new drm_fb_helper functions 2015-08-06 14:12:56 +02:00
ast drm/ast: Don't grab dev->struct_mutex for in mmap offset ioctl 2015-08-10 13:36:55 +02:00
atmel-hlcdc Linux 4.2-rc8 2015-08-24 16:36:42 +10:00
bochs drm/bochs: Don't grab dev->struct_mutex for in mmap offset ioctl 2015-08-10 13:37:04 +02:00
bridge Merge branch 'drm-dwhdmi-devel' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into drm-next 2015-08-27 13:01:57 +10:00
cirrus drm/cirrus: Don't grab dev->struct_mutex for in mmap offset ioctl 2015-08-10 13:37:27 +02:00
exynos media updates for v4.3-rc1 2015-09-11 16:42:39 -07:00
fsl-dcu drm/layerscape: fix handling fsl_dcu_drm_plane_index result 2015-09-24 08:13:09 +10:00
gma500 drm/gma500: Use new drm_fb_helper functions 2015-08-06 14:12:59 +02:00
i2c Merge remote-tracking branches 'asoc/topic/rcar', 'asoc/topic/reg-default', 'asoc/topic/rl6231', 'asoc/topic/rockchip' and 'asoc/topic/rt286' into asoc-next 2015-08-30 15:55:54 +01:00
i810
i915 drm/i915/skl: Don't call intel_prepare_ddi when encoder list isn't yet initialized. 2015-09-28 11:05:13 +03:00
imx Merge branch 'drm-dwhdmi-devel' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into drm-next 2015-08-27 13:01:57 +10:00
mga
mgag200 drm/mgag200: Fix driver_load error handling 2015-09-24 08:10:44 +10:00
msm gpu/drm: Kill off set_irq_flags usage 2015-09-16 16:53:38 +02:00
nouveau Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux 2015-09-11 09:35:56 -07:00
omapdrm drm/omap: Use new drm_fb_helper functions 2015-08-06 14:13:03 +02:00
panel drm/panel: Add support for LG LG4573 480x800 4.3" panel 2015-08-14 21:35:35 +02:00
qxl drm/qxl: only report first monitor as connected if we have no state 2015-09-24 08:08:17 +10:00
r128
radeon drm/radeon: add quirk for MSI R7 370 2015-09-23 17:23:47 -04:00
rcar-du drm/atomic: pass old crtc state to atomic_begin/flush. 2015-07-27 16:23:22 +02:00
rockchip drm/rockchip: vop: support plane scale 2015-08-26 14:16:26 +08:00
savage
shmobile drm: Simplify drm_for_each_legacy_plane arguments 2015-07-22 16:25:45 +02:00
sis
sti Merge branch 'drm-sti-next-atomic-2015-08-11' of http://git.linaro.org/people/benjamin.gaignard/kernel into drm-next 2015-08-14 10:14:23 +10:00
tdfx
tegra drm/tegra: Changes for v4.3-rc1 2015-08-17 15:52:39 +10:00
tilcdc drm/tilcdc: panel: make better use of gpiod API 2015-07-06 10:10:21 +02:00
ttm drm/ttm: Fix memory space allocation v2 2015-09-15 00:57:01 -07:00
udl drm/udl: Use new drm_fb_helper functions 2015-08-06 14:13:00 +02:00
vgem mm: mark most vm_operations_struct const 2015-09-10 13:29:01 -07:00
via treewide: fix typos in comment blocks 2015-08-07 14:46:24 +02:00
virtio drm/virtio: Use new drm_fb_helper functions 2015-08-06 14:13:07 +02:00
vmwgfx Merge tag 'vmwgfx-fixes-4.3-150924' of git://people.freedesktop.org/~thomash/linux into drm-fixes 2015-09-24 18:36:04 +10:00
ati_pcigart.c
drm_agpsupport.c
drm_atomic_helper.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-09-04 15:49:32 -07:00
drm_atomic.c drm/atomic: Fix bookkeeping with TEST_ONLY, v3. 2015-09-01 11:57:06 +03:00
drm_auth.c
drm_bridge.c
drm_bufs.c
drm_cache.c drm: Avoid the double clflush on the last cache line in drm_clflush_virt_range() 2015-06-19 17:25:17 +02:00
drm_context.c drm: Convert drm_legacy_ctxbitmap_init to void return type 2015-07-02 17:00:48 +02:00
drm_crtc_helper.c drm: Make the connector dpms callback return a value, v2. 2015-07-27 16:23:28 +02:00
drm_crtc_internal.h
drm_crtc.c Linux 4.2-rc7 2015-08-17 14:13:53 +10:00
drm_debugfs.c
drm_dma.c
drm_dp_helper.c drm/dp: Add dp_aux_i2c_speed_khz module param to set the assume i2c bus speed 2015-09-02 16:13:43 +03:00
drm_dp_mst_topology.c Linux 4.2-rc8 2015-08-24 16:36:42 +10:00
drm_drv.c Merge tag 'topic/connector-locking-2015-07-23' of git://anongit.freedesktop.org/drm-intel into drm-next 2015-07-24 14:30:29 +10:00
drm_edid_load.c
drm_edid.c drm/edid: Use ARRAY_SIZE in drm_add_modes_noedid 2015-08-11 12:04:16 +02:00
drm_encoder_slave.c
drm_fb_cma_helper.c drm/fb_cma_helper: Use new drm_fb_helper functions 2015-08-06 14:13:00 +02:00
drm_fb_helper.c drm/core: Set mode to NULL when connectors in a set drops to 0. 2015-08-11 12:04:19 +02:00
drm_flip_work.c
drm_fops.c drm/mode: Add user blob-creation ioctl 2015-05-22 16:18:28 +02:00
drm_gem_cma_helper.c drm/cma-helper: Don't grab dev->struct_mutex for in mmap offset ioctl 2015-08-10 13:37:36 +02:00
drm_gem.c drm/gem: Be more friendly with locking checks 2015-08-10 13:35:49 +02:00
drm_global.c
drm_hashtab.c
drm_info.c
drm_internal.h
drm_ioc32.c Merge tag 'topic/drm-misc-2015-07-23' of git://anongit.freedesktop.org/drm-intel into drm-next 2015-07-24 14:28:16 +10:00
drm_ioctl.c drm: Allow also control clients to check the drm version 2015-09-24 00:24:24 -07:00
drm_irq.c Linux 4.2-rc7 2015-08-17 14:13:53 +10:00
drm_legacy.h drm: Convert drm_legacy_ctxbitmap_init to void return type 2015-07-02 17:00:48 +02:00
drm_lock.c drm: Reject DRI1 hw lock ioctl functions for kms drivers 2015-07-02 17:00:48 +02:00
drm_memory.c
drm_mipi_dsi.c
drm_mm.c drm: clean up drm_mm debugfs output 2015-05-29 09:17:57 +10:00
drm_modes.c drm/mode: Unstatic kernel-userspace mode conversion 2015-05-22 16:18:21 +02:00
drm_modeset_lock.c drm: Remove __drm_modeset_lock_all 2015-08-06 14:13:02 +02:00
drm_of.c drm: Add modeset object iterators 2015-07-22 16:25:45 +02:00
drm_panel.c
drm_pci.c
drm_plane_helper.c drm/atomic: pass old crtc state to atomic_begin/flush. 2015-07-27 16:23:22 +02:00
drm_platform.c
drm_prime.c drm: prime: Document gem_prime_mmap 2015-06-19 17:50:05 +02:00
drm_probe_helper.c drm/probe-helper: Grab mode_config.mutex in poll_init/enable 2015-07-22 16:25:45 +02:00
drm_rect.c
drm_scatter.c
drm_sysfs.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-06-26 13:18:51 -07:00
drm_trace_points.c
drm_trace.h
drm_vm.c
drm_vma_manager.c
Kconfig Merge branch 'drm-next-fsl-dcu' of https://github.com/Jianwei-Wang/linux-drm-fsl-dcu into drm-next 2015-08-20 14:11:17 +10:00
Makefile drm/layerscape: Add Freescale DCU DRM driver 2015-08-19 22:23:04 -04:00