On Fri, 2020-01-24 at 14:20 -0500, Mikita Lipski wrote:
On 1/24/20 2:10 PM, Lyude Paul wrote:
Disabling a display on MST can potentially happen after the entire MST topology has been removed, which means that we can't communicate with the topology at all in this scenario. Likewise, this also means that we can't properly update payloads on the topology and as such, it's a good idea to ignore payload update failures when disabling displays. Currently, amdgpu makes the mistake of halting the payload update process when any payload update failures occur, resulting in leaving DC's local copies of the payload tables out of date.
This ends up causing problems with hotplugging MST topologies, and causes modesets on the second hotplug to fail like so:
[drm] Failed to updateMST allocation table forpipe idx:1 ------------[ cut here ]------------ WARNING: CPU: 5 PID: 1511 at drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:2677 update_mst_stream_alloc_table+0x11e/0x130 [amdgpu] Modules linked in: cdc_ether usbnet fuse xt_conntrack nf_conntrack nf_defrag_ipv6 libcrc32c nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 nft_counter nft_compat nf_tables nfnetlink tun bridge stp llc sunrpc vfat fat wmi_bmof uvcvideo snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi videobuf2_vmalloc snd_hda_intel videobuf2_memops videobuf2_v4l2 snd_intel_dspcfg videobuf2_common crct10dif_pclmul snd_hda_codec videodev crc32_pclmul snd_hwdep snd_hda_core ghash_clmulni_intel snd_seq mc joydev pcspkr snd_seq_device snd_pcm sp5100_tco k10temp i2c_piix4 snd_timer thinkpad_acpi ledtrig_audio snd wmi soundcore video i2c_scmi acpi_cpufreq ip_tables amdgpu(O) rtsx_pci_sdmmc amd_iommu_v2 gpu_sched mmc_core i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm crc32c_intel serio_raw hid_multitouch r8152 mii nvme r8169 nvme_core rtsx_pci pinctrl_amd CPU: 5 PID: 1511 Comm: gnome-shell Tainted: G O 5.5.0- rc7Lyude-Test+ #4 Hardware name: LENOVO FA495SIT26/FA495SIT26, BIOS R12ET22W(0.22 ) 01/31/2019 RIP: 0010:update_mst_stream_alloc_table+0x11e/0x130 [amdgpu] Code: 28 00 00 00 75 2b 48 8d 65 e0 5b 41 5c 41 5d 41 5e 5d c3 0f b6 06 49 89 1c 24 41 88 44 24 08 0f b6 46 01 41 88 44 24 09 eb 93 <0f> 0b e9 2f ff ff ff e8 a6 82 a3 c2 66 0f 1f 44 00 00 0f 1f 44 00 RSP: 0018:ffffac428127f5b0 EFLAGS: 00010202 RAX: 0000000000000002 RBX: ffff8d1e166eee80 RCX: 0000000000000000 RDX: ffffac428127f668 RSI: ffff8d1e166eee80 RDI: ffffac428127f610 RBP: ffffac428127f640 R08: ffffffffc03d94a8 R09: 0000000000000000 R10: ffff8d1e24b02000 R11: ffffac428127f5b0 R12: ffff8d1e1b83d000 R13: ffff8d1e1bea0b08 R14: 0000000000000002 R15: 0000000000000002 FS: 00007fab23ffcd80(0000) GS:ffff8d1e28b40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f151f1711e8 CR3: 00000005997c0000 CR4: 00000000003406e0 Call Trace: ? mutex_lock+0xe/0x30 dc_link_allocate_mst_payload+0x9a/0x210 [amdgpu] ? dm_read_reg_func+0x39/0xb0 [amdgpu] ? core_link_enable_stream+0x656/0x730 [amdgpu] core_link_enable_stream+0x656/0x730 [amdgpu] dce110_apply_ctx_to_hw+0x58e/0x5d0 [amdgpu] ? dcn10_verify_allow_pstate_change_high+0x1d/0x280 [amdgpu] ? dcn10_wait_for_mpcc_disconnect+0x3c/0x130 [amdgpu] dc_commit_state+0x292/0x770 [amdgpu] ? add_timer+0x101/0x1f0 ? ttm_bo_put+0x1a1/0x2f0 [ttm] amdgpu_dm_atomic_commit_tail+0xb59/0x1ff0 [amdgpu] ? amdgpu_move_blit.constprop.0+0xb8/0x1f0 [amdgpu] ? amdgpu_bo_move+0x16d/0x2b0 [amdgpu] ? ttm_bo_handle_move_mem+0x118/0x570 [ttm] ? ttm_bo_validate+0x134/0x150 [ttm] ? dm_plane_helper_prepare_fb+0x1b9/0x2a0 [amdgpu] ? _cond_resched+0x15/0x30 ? wait_for_completion_timeout+0x38/0x160 ? _cond_resched+0x15/0x30 ? wait_for_completion_interruptible+0x33/0x190 commit_tail+0x94/0x130 [drm_kms_helper] drm_atomic_helper_commit+0x113/0x140 [drm_kms_helper] drm_atomic_helper_set_config+0x70/0xb0 [drm_kms_helper] drm_mode_setcrtc+0x194/0x6a0 [drm] ? _cond_resched+0x15/0x30 ? mutex_lock+0xe/0x30 ? drm_mode_getcrtc+0x180/0x180 [drm] drm_ioctl_kernel+0xaa/0xf0 [drm] drm_ioctl+0x208/0x390 [drm] ? drm_mode_getcrtc+0x180/0x180 [drm] amdgpu_drm_ioctl+0x49/0x80 [amdgpu] do_vfs_ioctl+0x458/0x6d0 ksys_ioctl+0x5e/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x55/0x1b0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fab2121f87b Code: 0f 1e fa 48 8b 05 0d 96 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d dd 95 2c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd045f9068 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffd045f90a0 RCX: 00007fab2121f87b RDX: 00007ffd045f90a0 RSI: 00000000c06864a2 RDI: 000000000000000b RBP: 00007ffd045f90a0 R08: 0000000000000000 R09: 000055dbd2985d10 R10: 000055dbd2196280 R11: 0000000000000246 R12: 00000000c06864a2 R13: 000000000000000b R14: 0000000000000000 R15: 000055dbd2196280 ---[ end trace 6ea888c24d2059cd ]---
Note as well, I have only been able to reproduce this on setups with 2 MST displays.
Changes since v1:
- Don't return false when part 1 or part 2 of updating the payloads fails, we don't want to abort at any step of the process even if things fail
Signed-off-by: Lyude Paul lyude@redhat.com Acked-by: Harry Wentland harry.wentland@amd.com Cc: stable@vger.kernel.org
.../drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index 069b7a6f5597..318b474ff20e 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -216,7 +216,8 @@ bool dm_helpers_dp_mst_write_payload_allocation_table( drm_dp_mst_reset_vcpi_slots(mst_mgr, mst_port); }
- ret = drm_dp_update_payload_part1(mst_mgr);
- /* It's OK for this to fail */
- drm_dp_update_payload_part1(mst_mgr);
/* mst_mgr->->payloads are VC payload notify MST branch using DPCD or * AUX message. The sequence is slot 1-63 allocated sequence for each @@ -225,9 +226,6 @@ bool dm_helpers_dp_mst_write_payload_allocation_table( get_payload_table(aconnector, proposed_table);
- if (ret)
return false;Sorry for being picky, but I think this might cause compilation error on some systems for having unused variable (int ret). Its better just to strip out both ret integer declarations.
No problem! It wouldn't be fair if I was the only one who got to be picky anyway ;)
Otherwise the patch is good. Thanks again!
Reviewed-by: Mikita Lipski Mikita.Lipski@amd.com
Mikita
return true; } @@ -285,7 +283,6 @@ bool dm_helpers_dp_mst_send_payload_allocation( struct amdgpu_dm_connector *aconnector; struct drm_dp_mst_topology_mgr *mst_mgr; struct drm_dp_mst_port *mst_port;
- int ret;
aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context; @@ -299,10 +296,8 @@ bool dm_helpers_dp_mst_send_payload_allocation( if (!mst_mgr->mst_state) return false;
- ret = drm_dp_update_payload_part2(mst_mgr);
- if (ret)
return false;
- /* It's OK for this to fail */
- drm_dp_update_payload_part2(mst_mgr);
if (!enable) drm_dp_mst_deallocate_vcpi(mst_mgr, mst_port);