Hi all,
I've noticed that on the tip of drm-next vcn playback of video is broken
(see dmesg below). I've bisected it to this commit
[root at raven linux]# git bisect good
701372349fd55b5396b335580e979ac4dde3dd02 is the first bad commit
commit 701372349fd55b5396b335580e979ac4dde3dd02
Author: Alex Deucher <alexander.deucher at amd.com>
Date: Tue Mar 27 17:10:56 2018 -0500
drm/amdgpu/gmc9: use amdgpu_ring_emit_reg_write_reg_wait in gpu tlb
flush
Use amdgpu_ring_emit_reg_write_reg_wait. On engines that support it,
it provides a write and wait in a single packet which avoids a missed
ack if a world switch happens between the request and waiting for the
ack.
Reviewed-by: Huang Rui <ray.huang at amd.com>
Reviewed-by: Christian König <christian.koenig at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
:040000 040000 4e4312de03f4b34abd65f4bb12dba4c7093055ba
ccc4abc78c0b6f24328fd998f998fa06bf0618b1 M drivers
Which is odd because the commit before this is the vcn change and it
works fine (playing BBB right now).
Here's the dmesg:
[ 2925.640102] BUG: unable to handle kernel NULL pointer dereference at
0000000000000000
[ 2925.640113] IP: (null)
[ 2925.640116] PGD 0 P4D 0
[ 2925.640122] Oops: 0010 [#1] SMP KASAN NOPTI
[ 2925.640126] Modules linked in: tun fuse amdkfd amdgpu mfd_core chash
gpu_sched ttm ax88179_178a usbnet
[ 2925.640139] CPU: 4 PID: 3791 Comm: vcn_dec Not tainted 4.16.0-rc7+ #20
[ 2925.640142] Hardware name: System manufacturer System Product
Name/TUF B350M-PLUS GAMING, BIOS 3803 01/22/2018
[ 2925.640146] RIP: 0010: (null)
[ 2925.640148] RSP: 0018:ffff8801d54f7790 EFLAGS: 00010206
[ 2925.640153] RAX: 0000000000000000 RBX: ffff8801d8b38420 RCX:
00000000007c0080
[ 2925.640156] RDX: 000000000001a6fa RSI: 000000000001a6e8 RDI:
ffff8801d8b38420
[ 2925.640159] RBP: 000000000001a6fa R08: 0000000000000080 R09:
ffffed003aa9eef9
[ 2925.640162] R10: 0000000009c74f08 R11: fffffbfff0f5d1e7 R12:
ffff8801d8b3277c
[ 2925.640164] R13: ffff8801d8b3001c R14: 0000000000000005 R15:
0000000000000000
[ 2925.640168] FS: 0000000000000000(0000) GS:ffff8801dcf00000(0000)
knlGS:0000000000000000
[ 2925.640171] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2925.640174] CR2: 0000000000000000 CR3: 00000001d9712000 CR4:
00000000003406e0
[ 2925.640176] Call Trace:
[ 2925.640272] ? gmc_v9_0_emit_flush_gpu_tlb+0x260/0x2a0 [amdgpu]
[ 2925.640368] ? vcn_v1_0_dec_ring_insert_start+0x360/0x360 [amdgpu]
[ 2925.640459] ? mmhub_v1_0_get_clockgating+0xc0/0xc0 [amdgpu]
[ 2925.640545] ? amdgpu_vmid_had_gpu_reset+0x89/0xc0 [amdgpu]
[ 2925.640640] ? vcn_v1_0_dec_ring_emit_vm_flush+0x64/0xb0 [amdgpu]
[ 2925.640725] ? amdgpu_vm_flush+0xb43/0xcc0 [amdgpu]
[ 2925.640810] ? amdgpu_vm_need_pipeline_sync+0x260/0x260 [amdgpu]
[ 2925.640897] ? amdgpu_vmid_had_gpu_reset+0xc0/0xc0 [amdgpu]
[ 2925.641003] ? vcn_v1_0_dec_ring_insert_start+0x2d7/0x360 [amdgpu]
[ 2925.641095] ? amdgpu_ib_schedule+0x1b5/0x800 [amdgpu]
[ 2925.641102] ? dma_fence_add_callback+0x15f/0x360
[ 2925.641201] ? amdgpu_job_run+0x32f/0x370 [amdgpu]
[ 2925.641297] ? amdgpu_job_free_resources+0xd0/0xd0 [amdgpu]
[ 2925.641302] ? __queue_delayed_work+0x144/0x1d0
[ 2925.641306] ? delayed_work_timer_fn+0x40/0x40
[ 2925.641312] ? prepare_to_wait_exclusive+0x1d0/0x1d0
[ 2925.641318] ? drm_sched_main+0x68c/0x940 [gpu_sched]
[ 2925.641323] ? drm_sched_entity_fini+0x60/0x60 [gpu_sched]
[ 2925.641328] ? save_stack+0x89/0xb0
[ 2925.641332] ? wait_woken+0x110/0x110
[ 2925.641337] ? ret_from_fork+0x22/0x40
[ 2925.641343] ? __schedule+0xd30/0xd30
[ 2925.641346] ? remove_wait_queue+0x150/0x150
[ 2925.641353] ? rcu_note_context_switch+0x2a0/0x2a0
[ 2925.641359] ? __lock_text_start+0x8/0x8
[ 2925.641367] ? drm_sched_entity_fini+0x60/0x60 [gpu_sched]
[ 2925.641371] ? kthread+0x19b/0x1c0
[ 2925.641376] ? kthread_create_worker_on_cpu+0xc0/0xc0
[ 2925.641382] ? ret_from_fork+0x22/0x40
[ 2925.641387] Code: Bad RIP value.
[ 2925.641397] RIP: (null) RSP: ffff8801d54f7790
[ 2925.641400] CR2: 0000000000000000
[ 2925.641405] ---[ end trace 0684cc0468f60fb1 ]---
Note that regular compute/gfx workflows work fine on the tip of drm-next
only vcn playback triggeers this (haven't tried encode yet...).
Cheers,
Tom
