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

Gustavo Padovan gustavo.padovan at collabora.co.uk
Tue Apr 7 11:39:59 PDT 2015


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disable instead of outdated -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?

	Gustavo


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