[PATCH -v3 00/11] drm/exynos: Add atomic modesetting support

Inki Dae inki.dae at samsung.com
Wed Apr 8 08:14:07 PDT 2015


On 2015년 04월 08일 03:39, Gustavo Padovan wrote:
> Hi Inki,
> 
> 2015-04-07 Inki Dae <inki.dae at samsung.com>:
> 
>> On 2015년 04월 07일 00:44, Inki Dae wrote:
>>> 2015-04-06 19:46 GMT+09:00 Inki Dae <inki.dae at samsung.com>:
>>>> On 2015년 04월 04일 03:09, Gustavo Padovan wrote:
>>>>> From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
>>>>>
>>>>> Hi,
>>>>>
>>>>> Here goes the full support for atomic modesetting on exynos. I've
>>>>> split the patches in the various phases of atomic support.
>>>>>
>>>>> These patches sits on top of the clean up patches I've sent yesterday
>>>>> to this mailing list[1].
>>>>>
>>>>> v2: fixes comments by Joonyoung
>>>>>         - remove unused var in patch 09
>>>>>         - use ->disable instead of outdated ->dpms in hdmi code
>>>>>         - remove WARN_ON from crtc enable/disable
>>>>>
>>>>> v3: fixes comment by Joonyoung
>>>>>       - move the removal of drm_helper_disable_unused_functions() to
>>>>>       separated patch
>>>>
>>>> With this patch series, Kernel booting is halted at end of kernel
>>>> booting. I tested this patch series on Trats2 board based on Exynos4412 SoC.
>>>>
>>>> Below is a part of full booting logs, which was halted,
>>>> [    1.992015] exynos-drm-ipp exynos-drm-ipp: drm ipp registered
>>>> successfully.
>>>> [    1.993009] exynos-drm exynos-drm: bound exynos-drm-vidi (ops
>>>> vidi_component_ops)
>>>> [    1.993036] exynos-drm exynos-drm: bound 11c00000.fimd (ops
>>>> fimd_component_ops)
>>>> [    1.993385] exynos-drm exynos-drm: bound 11c80000.dsi (ops
>>>> exynos_dsi_component_ops)
>>>> [    1.993390] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
>>>> [    1.993393] [drm] No driver support for vblank timestamp query.
>>>> [    1.993442] [drm] Initialized exynos 1.0.0 20110530 on minor 0
>>>> [    2.043358] WARNING: CPU: 2 PID: 1209 at drivers/clk/clk.c:898
>>>> clk_unprepare+0x24/0x2c()
>>>> [    2.051412] Modules linked in:
>>>> [    2.054422] CPU: 2 PID: 1209 Comm: kworker/2:1 Tainted: G        W
>>>>     4.0.0-rc6-00526-gc49d7de-dirty #1278
>>>> [    2.064337] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
>>>> [    2.070428] Workqueue: pm pm_runtime_work>
>>>>
>>>> After that, I tested it again without FIMD and the booting is ok. So I
>>>> guess that this atomic feature has a bug to FIMD driver.
>>>>
>>>
>>> More information,
>>>
>>> The reason the booting is halted is that a deadlock occurs at fbcon
>>> module when register_framebuffer() is called.
>>>
>>> Below are our test results,
>>> - with only cleanup series, FIMD and HDMI work well.
>>> - with cleanup and atomic series, HDMI works well but FIMD doesn't
>>> work - a deadlock occurs.
>>>
>>> Could anyone test it with the atomic series on trats2 board? You can
>>> test it on top of exynos-drm-next-todo branch which contains all
>>> relevant patches,
>>> https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm-exynos.git/log/?h=exynos-drm-next-todo
>>>
>>> Anyway, we will continue to take a look at the this issue why the
>>> deadlock occurs.
>>
>> In addition,
>>
>> I added some codes temporarily to fbmem module which mitigates the
>> deadlock issue. After that, I see below panic log,
>>
>> [    3.254840] Unable to handle kernel NULL pointer dereference at
>> virtual address 000000a4
>> [    3.262870] pgd = c0004000
>> [    3.265539] [000000a4] *pgd=00000000
>> [    3.269102] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
>> [    3.274392] Modules linked in:
>> [    3.277435] CPU: 2 PID: 1 Comm: swapper/0 Tainted: G        W
>> 4.0.0-rc6-00526-gc49d7de-dirty #1308
>> [    3.286892] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
>> [    3.292970] task: ee878000 ti: ee880000 task.ti: ee880000
>> [    3.298356] PC is at exynos_plane_atomic_update+0x24/0x1d4
>> [    3.303824] LR is at drm_atomic_helper_commit_planes+0xa4/0x18c
>> [    3.309723] pc : [<c028bff4>]    lr : [<c0265308>]    psr: 60000113
>> [    3.309723] sp : ee881b38  ip : 00000020  fp : 00000000
>> [    3.321179] r10: c04cfc00  r9 : 00000008  r8 : eebfb9c0
>> [    3.326387] r7 : 00000002  r6 : 00000000  r5 : 00000000  r4 : ee925308
>> [    3.332897] r3 : ee329fc0  r2 : 00000000  r1 : 00000000  r0 : ee925308
>> [    3.339409] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM
>> Segment kernel
>> [    3.346699] Control: 10c5387d  Table: 4000404a  DAC: 00000015
>> [    3.352427] Process swapper/0 (pid: 1, stack limit = 0xee880210)
>> [    3.358416] Stack: (0xee881b38 to 0xee882000)
>> [    3.362757] 1b20:
>>    c0726794 00000008
>> [    3.370919] 1b40: 00000002 ee925308 00000000 ee329e00 00000002
>> eebfb9c0 00000008 c04cfc00
>> [    3.379078] 1b60: 00000000 c0265308 00000008 00000000 ee329e00
>> ee0a8000 00000008 00000000
>> [    3.387237] 1b80: 00000000 c0267304 ee329e00 ee8efe00 ee914c00
>> 00000002 00000000 00000002
>> [    3.395396] 1ba0: 00000000 c026609c c0265ef0 00000000 ee914c00
>> 00000028 ee8eff00 00000001
>> [    3.403555] 1bc0: 00000000 c06c8380 00000000 c02770d0 ee8efe00
>> 00000000 00000028 ee8eff00
>> [    3.411714] 1be0: 00000001 c0267a2c ee0a8000 c0286214 ee8eff00
>> ee8eff00 ee0a8000 00000000
>> [    3.419874] 1c00: 00000000 c0722ad4 ee35e000 c0269900 00000000
>> ee915400 00000000 c0269958
>> [    3.428033] 1c20: ee808c00 c020cc8c c0248620 c05d5448 ee808c00
>> ee808c00 ee808d34 00000000
>> [    3.436192] 1c40: 00000000 00000001 00000066 c0724acc c0724fd4
>> 0000005b 00000066 0000005b
>> [    3.444351] 1c60: c05b28cc ee808c00 ee808d74 00000000 00000000
>> 00000001 ee808c00 00000000
>> [    3.452511] 1c80: 00000001 c0246564 c04b4950 00000000 c0724fdc
>> c07250f0 00000001 c0248568
>> [    3.460670] 1ca0: c049cc58 c06ce2e4 00000000 0000003e c070da2c
>> c05d09ec 00000000 c0724fcc
>> [    3.468829] 1cc0: 00000000 c04b4950 c0724fe8 00000000 00000000
>> 00000000 0000003e 00000000
>> [    3.476988] 1ce0: c0725604 c0248de0 c05d54ac 00000001 ee074780
>> 00000001 c0724920 c06c8380
>> [    3.485148] 1d00: c0724acc 00008380 00000005 00000000 00000000
>> 01d00000 00000000 c020cd5c
>> [    3.493306] 1d20: c06c8754 ffffffff ee881d88 c0039890 c06c8754
>> 00000005 ee881d88 ffffffff
>> [    3.501466] 1d40: ee915644 ee91540c 01d00000 c0039bec 00000000
>> 00000000 ee915644 c06badb8
>> [    3.509625] 1d60: ee915400 c06badb8 00000000 c0039c1c 00000000
>> ee915400 c06badb8 c0215980
>> [    3.517784] 1d80: c05d101c 00000000 ee915400 00000000 00000000
>> 00000000 000002d0 00000500
>> [    3.525943] 1da0: 00000000 00000000 00000000 00000000 00000000
>> 00000000 00000000 00000000
>> [    3.534103] 1dc0: 00000000 00000020 ee8efe50 ee8eff00 ee915400
>> 00000001 ee8efe50 c0726794
>> [    3.542262] 1de0: 00000002 c0269bc4 000002d0 00000500 000002d0
>> 00000500 00000020 00000018
>> [    3.550421] 1e00: ee0a8000 00000000 eebfbdc0 ee8eff00 ee0a8190
>> c028a374 ee0a8288 00000001
>> [    3.558580] 1e20: ee0a8294 ee0a8000 ee0a8190 c025ff20 00000000
>> c0491308 c06933e0 c0492b3c
>> [    3.566740] 1e40: ee08b374 ee914428 ee9000d4 ee08b200 ee08b208
>> 00000000 00000098 c06933e0
>> [    3.574899] 1e60: 00000000 c028e764 ee08b200 c0288088 ee9000d0
>> ee9000d4 ee08b200 c029c5bc
>> [    3.583058] 1e80: c0726874 ee08b208 c06d42a4 00000000 00000000
>> c02a2504 ee08b208 c06d42a4
>> [    3.591217] 1ea0: ee08b23c c06d2b7c eebf83c0 c02a2708 00000000
>> c06d42a4 c02a267c c02a0ad8
>> [    3.599376] 1ec0: ee9bf674 ee06db40 c06d42a4 ee06df00 00000000
>> c02a1d2c c05dee34 c06bcbe0
>> [    3.607535] 1ee0: c0681fc8 c06d42a4 c06bcbe0 c0681fc8 00000000
>> c02a2d04 c06bcbe0 c06bcbe0
>> [    3.615695] 1f00: c0681fc8 c0008990 ee855980 c04971d0 00000025
>> 00000000 60000100 c06c066c
>> [    3.623854] 1f20: 00000000 c06c066c 60000113 00000003 ef7fc9ed
>> ef7fc9de c04a96e8 c00384d0
>> [    3.632013] 1f40: c05f26cc ef7fc9fc 00000006 00000006 c06c0648
>> ef7fc940 c06b3f98 00000006
>> [    3.640172] 1f60: c06933d8 c06eabc0 c06eabc0 00000098 c06933e0
>> c0668dac 00000006 00000006
>> [    3.648331] 1f80: c0668594 c003c944 0000abc0 c048bed0 00000000
>> 00000000 00000000 00000000
>> [    3.656490] 1fa0: 00000000 c048bedc 00000000 c000e7c0 00000000
>> 00000000 00000000 00000000
>> [    3.664649] 1fc0: 00000000 00000000 00000000 00000000 00000000
>> 00000000 00000000 00000000
>> [    3.672809] 1fe0: 00000000 00000000 00000000 00000000 00000013
>> 00000000 ffffffff ffffffff
>> [    3.680977] [<c028bff4>] (exynos_plane_atomic_update) from
>> [<c0265308>] (drm_atomic_helper_commit_planes+0xa4/0x18c)
>> [    3.691475] [<c0265308>] (drm_atomic_helper_commit_planes) from
>> [<c0267304>] (drm_atomic_helper_commit+0xec/0x144)
>> [    3.701804] [<c0267304>] (drm_atomic_helper_commit) from [<c026609c>]
>> (drm_atomic_helper_set_config+0x1ac/0x3d0)
>> [    3.711962] [<c026609c>] (drm_atomic_helper_set_config) from
>> [<c02770d0>] (drm_mode_set_config_internal+0x58/0xd4)
>> [    3.722288] [<c02770d0>] (drm_mode_set_config_internal) from
>> [<c0267a2c>] (restore_fbdev_mode+0xd4/0xf4)
>> [    3.731749] [<c0267a2c>] (restore_fbdev_mode) from [<c0269900>]
>> (drm_fb_helper_restore_fbdev_mode_unlocked+0x1c/0x5c)
>> [    3.742338] [<c0269900>] (drm_fb_helper_restore_fbdev_mode_unlocked)
>> from [<c0269958>] (drm_fb_helper_set_par+0x18/0x34)
>> [    3.753191] [<c0269958>] (drm_fb_helper_set_par) from [<c020cc8c>]
>> (fbcon_init+0x5c8/0x614)
>> [    3.761525] [<c020cc8c>] (fbcon_init) from [<c0246564>]
>> (visual_init+0xa4/0xec)
>>
>> exynos_plane_atomic_update function calls internally
>> exynos_plane_mode_set function, and this call incurs a panic because
>> exynos_plane_mode_set function is called with null argument -
>> state->crtc is null.
> 
> I just checked the value of state->crtc for me at this point of the flow
> and it is not NULL. I wonder why this works differently for your board.
> Could you check if state is null or if state->crtc is null?

state->crtc is null. For the test, I added printk - which prints out
address values of state and state->crtc address - to
exynos_plane_atomic_update function.

Below is the test result,
# modetest -v -s 25 at 23:720x1280 -P 23:100x100+0+0
[    5.457989] exynos_plane_atomic_update: state = eea11880, state->crtc
= ee914c00
...snip...
[    7.005817] exynos_plane_atomic_update: state = ee265b40, state->crtc
= ee914c00
[    7.089881] exynos_plane_atomic_update: state = ee265780, state->crtc
=   (null)
[    7.095823] Unable to handle kernel NULL pointer dereference at
virtual address 000000a4
[    7.103884] pgd = c0004000
[    7.106581] [000000a4] *pgd=00000000
[    7.110120] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[    7.115497] Modules linked in:
[    7.118540] CPU: 0 PID: 1458 Comm: modetest Not tainted
4.0.0-rc6-00526-gc49d7de-dirty #1329
[    7.126955] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[    7.133033] task: ee1eee80 ti: ee1be000 task.ti: ee1be000
[    7.138426] PC is at exynos_plane_atomic_update+0x60/0x200
[    7.143882] LR is at 0x0
[    7.146401] pc : [<c028c014>]    lr : [<00000000>]    psr: 60000013
[    7.146401] sp : ee1bfde0  ip : 00000000  fp : 00000000
[    7.157856] r10: 00000000  r9 : 00000000  r8 : 00000000
[    7.163065] r7 : 00000000  r6 : 00000000  r5 : 00000000  r4 : ee926228
[    7.169574] r3 : 00000004  r2 : 00000000  r1 : 00000000  r0 : 00000000
[    7.176086] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM
Segment user
[    7.183202] Control: 10c5387d  Table: 6dc2004a  DAC: 00000015
[    7.188932] Process modetest (pid: 1458, stack limit = 0xee1be210)
[    7.195094] Stack: (0xee1bfde0 to 0xee1c0000)
[    7.199438] fde0: 00000000 ee265740 c071dd14 00000005 00000001
ee926228 00000001 ee265740
[    7.207597] fe00: 00000001 ee265c80 00000005 c04c9c18 00100100
c0265314 00000005 00000000
[    7.215755] fe20: ee265740 ee350000 00000005 00000000 ee350000
c0267310 00000000 ee265780
[    7.223915] fe40: ee926228 ee265740 ee350000 ee350260 ee350000
c0265ed0 ee926228 eeafb840
[    7.232074] fe60: ee350000 ee3502b0 ee350000 c027717c ee926228
eeafb840 ee350000 c02772a4
[    7.240233] fe80: ee3501ec ee3501ec ee3501ec c0704fac 60000013
c048acd0 ee350260 c0704fac
[    7.248392] fea0: 60000013 eeafb840 ee369b40 ee369b40 edcd4c64
c027c180 edcd4ca8 edcd4c00
[    7.256551] fec0: 00200200 ee350000 ee350034 edcd4ca4 ee350000
c026d51c ee419558 00000001
[    7.264711] fee0: ee17bf00 ee350154 60000013 00000000 ee419558
edcd4300 edc50598 00000000
[    7.272869] ff00: ee8ee510 ee6b3428 00000008 edcd4308 00000000
c00cd6a8 00000000 00000000
[    7.281029] ff20: ee1ef1f4 00000000 c06e3d40 ee1eee80 ee1ef204
ee1be000 00000000 c0037594
[    7.289188] ff40: ee1eee80 edc561c0 00000001 ee1bff60 ee1ef204
c00222d8 0001d008 c00ccb30
[    7.297348] ff60: 00000000 00000000 0001d008 eebd8c80 00000000
b6ef2750 000000f8 c000e8a4
[    7.305506] ff80: ee1be000 00000000 00000000 c002378c 0006560a
00000000 b6ef2750 c0023814
[    7.313666] ffa0: 0006560a c000e720 0006560a 00000000 00000000
000655f0 00000000 b6f4d4c0
[    7.321825] ffc0: 0006560a 00000000 b6ef2750 000000f8 00000000
00000000 b6f51000 00000000
[    7.329984] ffe0: 000000f8 beac7a7c b6e8eaf7 b6e41946 60000030
00000000 6f7fd821 6f7fdc21
[    7.338162] [<c028c014>] (exynos_plane_atomic_update) from
[<c0265314>] (drm_atomic_helper_commit_planes+0xa4/0x18c)
[    7.348652] [<c0265314>] (drm_atomic_helper_commit_planes) from
[<c0267310>] (drm_atomic_helper_commit+0xec/0x144)
[    7.358979] [<c0267310>] (drm_atomic_helper_commit) from [<c0265ed0>]
(drm_atomic_helper_disable_plane+0xcc/0xf8)
[    7.369224] [<c0265ed0>] (drm_atomic_helper_disable_plane) from
[<c027717c>] (drm_plane_force_disable+0x24/0x5c)
[    7.379376] [<c027717c>] (drm_plane_force_disable) from [<c02772a4>]
(drm_framebuffer_remove+0xf0/0x108)
[    7.388838] [<c02772a4>] (drm_framebuffer_remove) from [<c027c180>]
(drm_fb_release+0x70/0x88)
[    7.397432] [<c027c180>] (drm_fb_release) from [<c026d51c>]
(drm_release+0x41c/0x4c8)
[    7.405245] [<c026d51c>] (drm_release) from [<c00cd6a8>]
(__fput+0x80/0x1c8)
[    7.412279] [<c00cd6a8>] (__fput) from [<c0037594>]
(task_work_run+0xac/0xe4)
[    7.419398] [<c0037594>] (task_work_run) from [<c00222d8>]
(do_exit+0x2e8/0x980)
[    7.426769] [<c00222d8>] (do_exit) from [<c002378c>]
(do_group_exit+0x4c/0xc4)
[    7.433971] [<c002378c>] (do_group_exit) from [<c0023814>]
(__wake_up_parent+0x0/0x18)
[    7.441870] Code: e1d592b2 e1d502b6 e1d5a2be e1d552ba (e59630a4)
[    7.447990] ---[ end trace 3cb27f1bd07f8c05 ]---
[    7.452561] Fixing recursive fault but reboot is needed!

However, please know that I disabled other crtc drivers for the test
because with only fimd enabled, kernel booting was ok and at least I
could test modetest app although I faced with a kernel panic. As I
mentioned already, with crtc drivers more than two, kernel booting is
halted.

P.s. I tested it on exynos-drm-next-todo branch. If you tried to test it
on other branch, then please test it on same branch, exynos-drm-next-todo.

Thanks,
Inki Dae

> 
> 	Gustavo
> 



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