Hi, Thorsten here, the Linux kernel's regression tracker. Top-posting for once, to make this easily accessible to everyone. Dmitry, was any progress made to address this regression? Doesn't look like it, but I strongly suspect I'm missing something, as I'm not really sure if I properly understood this thread. It sounded a bit like a4e771729a51 should be reverted for now until all drm_kms_helper_poll_disable() calls have been verified. Is that right? Or did somebody already verify and fix all of them with bugs? Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page. #regzbot poke On 28.04.23 03:17, zongmin zhou wrote: > On Wed, 2023-04-26 at 16:10 +0300, Dmitry Baryshkov wrote: >> On Wed, 26 Apr 2023 at 12:09, zongmin zhou <zhouzongmin@xxxxxxxxxx> >> wrote: >>> On Sun, 2023-04-23 at 22:51 +0200, Janne Grunau wrote: >>>> On 2023-04-20 23:07:01 +0300, Dmitry Baryshkov wrote: >>>>> On Thu, 20 Apr 2023 at 23:01, Janne Grunau <j@xxxxxxxxxx> >>>>> wrote: >>>>>> >>>>>> On 2023-03-28 10:31:29 +0800, Zongmin Zhou wrote: >>>>>>> When drivers call drm_kms_helper_poll_disable from >>>>>>> their device suspend implementation without enabled output >>>>>>> polling before, >>>>>>> following warning will be reported,due to work->func not be >>>>>>> initialized: >>>>>> >>>>>> we see the same warning with the wpork in progress kms driver >>>>>> for >>>>>> apple >>>>>> silicon SoCs. The connectors do not need to polled so the >>>>>> driver >>>>>> never >>>>>> calls drm_kms_helper_poll_init(). >>>>>> >>>>>>> [ 55.141361] WARNING: CPU: 3 PID: 372 at >>>>>>> kernel/workqueue.c:3066 __flush_work+0x22f/0x240 >>>>>>> [ 55.141382] Modules linked in: nls_iso8859_1 >>>>>>> snd_hda_codec_generic ledtrig_audio snd_hda_intel >>>>>>> snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec >>>>>>> snd_hda_core >>>>>>> snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event >>>>>>> snd_rawmidi >>>>>>> snd_seq intel_rapl_msr intel_rapl_common bochs >>>>>>> drm_vram_helper >>>>>>> drm_ttm_helper snd_seq_device nfit ttm crct10dif_pclmul >>>>>>> snd_timer ghash_clmulni_intel binfmt_misc sha512_ssse3 >>>>>>> aesni_intel drm_kms_helper joydev input_leds syscopyarea >>>>>>> crypto_simd snd cryptd sysfillrect sysimgblt mac_hid >>>>>>> serio_raw >>>>>>> soundcore qemu_fw_cfg sch_fq_codel msr parport_pc ppdev lp >>>>>>> parport drm ramoops reed_solomon pstore_blk pstore_zone >>>>>>> efi_pstore virtio_rng ip_tables x_tables autofs4 >>>>>>> hid_generic >>>>>>> usbhid hid ahci virtio_net i2c_i801 crc32_pclmul psmouse >>>>>>> virtio_scsi libahci i2c_smbus lpc_ich xhci_pci net_failover >>>>>>> virtio_blk xhci_pci_renesas failover >>>>>>> [ 55.141430] CPU: 3 PID: 372 Comm: kworker/u16:9 Not >>>>>>> tainted >>>>>>> 6.2.0-rc6+ #16 >>>>>>> [ 55.141433] Hardware name: QEMU Standard PC (Q35 + ICH9, >>>>>>> 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org >>>>>>> 04/01/2014 >>>>>>> [ 55.141435] Workqueue: events_unbound async_run_entry_fn >>>>>>> [ 55.141441] RIP: 0010:__flush_work+0x22f/0x240 >>>>>>> [ 55.141444] Code: 8b 43 28 48 8b 53 30 89 c1 e9 f9 fe ff >>>>>>> ff >>>>>>> 4c 89 f7 e8 b5 95 d9 00 e8 00 53 08 00 45 31 ff e9 11 ff ff >>>>>>> ff >>>>>>> 0f 0b e9 0a ff ff ff <0f> 0b 45 31 ff e9 00 ff ff ff e8 e2 >>>>>>> 54 >>>>>>> d8 00 66 90 90 90 90 90 90 >>>>>>> [ 55.141446] RSP: 0018:ff59221940833c18 EFLAGS: 00010246 >>>>>>> [ 55.141449] RAX: 0000000000000000 RBX: 0000000000000000 >>>>>>> RCX: >>>>>>> ffffffff9b72bcbe >>>>>>> [ 55.141450] RDX: 0000000000000001 RSI: 0000000000000001 >>>>>>> RDI: >>>>>>> ff3ea01e4265e330 >>>>>>> [ 55.141451] RBP: ff59221940833c90 R08: 0000000000000000 >>>>>>> R09: >>>>>>> 8080808080808080 >>>>>>> [ 55.141453] R10: ff3ea01e42b3caf4 R11: 000000000000000f >>>>>>> R12: >>>>>>> ff3ea01e4265e330 >>>>>>> [ 55.141454] R13: 0000000000000001 R14: ff3ea01e505e5e80 >>>>>>> R15: >>>>>>> 0000000000000001 >>>>>>> [ 55.141455] FS: 0000000000000000(0000) >>>>>>> GS:ff3ea01fb7cc0000(0000) knlGS:0000000000000000 >>>>>>> [ 55.141456] CS: 0010 DS: 0000 ES: 0000 CR0: >>>>>>> 0000000080050033 >>>>>>> [ 55.141458] CR2: 0000563543ad1546 CR3: 000000010ee82005 >>>>>>> CR4: >>>>>>> 0000000000771ee0 >>>>>>> [ 55.141464] DR0: 0000000000000000 DR1: 0000000000000000 >>>>>>> DR2: >>>>>>> 0000000000000000 >>>>>>> [ 55.141465] DR3: 0000000000000000 DR6: 00000000fffe0ff0 >>>>>>> DR7: >>>>>>> 0000000000000400 >>>>>>> [ 55.141466] PKRU: 55555554 >>>>>>> [ 55.141467] Call Trace: >>>>>>> [ 55.141469] <TASK> >>>>>>> [ 55.141472] ? pcie_wait_cmd+0xdf/0x220 >>>>>>> [ 55.141478] ? mptcp_seq_show+0xe0/0x180 >>>>>>> [ 55.141484] __cancel_work_timer+0x124/0x1b0 >>>>>>> [ 55.141487] cancel_delayed_work_sync+0x17/0x20 >>>>>>> [ 55.141490] drm_kms_helper_poll_disable+0x26/0x40 >>>>>>> [drm_kms_helper] >>>>>>> [ 55.141516] drm_mode_config_helper_suspend+0x25/0x90 >>>>>>> [drm_kms_helper] >>>>>>> [ 55.141531] ? __pm_runtime_resume+0x64/0x90 >>>>>>> [ 55.141536] bochs_pm_suspend+0x16/0x20 [bochs] >>>>>>> [ 55.141540] pci_pm_suspend+0x8b/0x1b0 >>>>>>> [ 55.141545] ? __pfx_pci_pm_suspend+0x10/0x10 >>>>>>> [ 55.141547] dpm_run_callback+0x4c/0x160 >>>>>>> [ 55.141550] __device_suspend+0x14c/0x4c0 >>>>>>> [ 55.141553] async_suspend+0x24/0xa0 >>>>>>> [ 55.141555] async_run_entry_fn+0x34/0x120 >>>>>>> [ 55.141557] process_one_work+0x21a/0x3f0 >>>>>>> [ 55.141560] worker_thread+0x4e/0x3c0 >>>>>>> [ 55.141563] ? __pfx_worker_thread+0x10/0x10 >>>>>>> [ 55.141565] kthread+0xf2/0x120 >>>>>>> [ 55.141568] ? __pfx_kthread+0x10/0x10 >>>>>>> [ 55.141570] ret_from_fork+0x29/0x50 >>>>>>> [ 55.141575] </TASK> >>>>>>> [ 55.141575] ---[ end trace 0000000000000000 ]--- >>>>>>> >>>>>>> Fixes: a4e771729a51 ("drm/probe_helper: sort out >>>>>>> poll_running >>>>>>> vs poll_enabled") >>>>>>> Signed-off-by: Zongmin Zhou<zhouzongmin@xxxxxxxxxx> >>>>>>> --- >>>>>>> drivers/gpu/drm/drm_probe_helper.c | 3 ++- >>>>>>> 1 file changed, 2 insertions(+), 1 deletion(-) >>>>>>> >>>>>>> diff --git a/drivers/gpu/drm/drm_probe_helper.c >>>>>>> b/drivers/gpu/drm/drm_probe_helper.c >>>>>>> index 8127be134c39..ac72b18e2257 100644 >>>>>>> --- a/drivers/gpu/drm/drm_probe_helper.c >>>>>>> +++ b/drivers/gpu/drm/drm_probe_helper.c >>>>>>> @@ -855,7 +855,8 @@ void drm_kms_helper_poll_disable(struct >>>>>>> drm_device *dev) >>>>>>> if (dev->mode_config.poll_running) >>>>>>> drm_kms_helper_disable_hpd(dev); >>>>>>> >>>>>>> - cancel_delayed_work_sync(&dev- >>>>>>>> mode_config.output_poll_work); >>>>>>> + if (dev->mode_config.poll_enabled) >>>>>>> + cancel_delayed_work_sync(&dev- >>>>>>>> mode_config.output_poll_work); >>>>>> >>>>>> Checking for dev->mode_config.poll_enabled at the start of >>>>>> the >>>>>> function >>>>>> and return early if it is not true looks more in style with >>>>>> the >>>>>> rest of >>>>>> drm_probe_helper.c. >>>>> >>>>> I think it is an error to call drm_kms_helper_poll_disable() if >>>>> polling was not initialized. So, in my opinion the fix should >>>>> go to >>>>> the drm_mode_config_helper_suspend() / _resume() instead. >>>>> Please >>>>> add a >>>>> guard there using dev->mode_config.poll_enabled. >>>> >>>> While I tend to agree to the sentiment I do not think this is the >>>> correct fix in this situation. drm_kms_helper_poll_disable had >>>> the >>>> check since at least 2014. a4e771729a51 is a regression. If we >>>> want >>>> to >>>> change the behavior it should be done explicitly and after >>>> verifying >>>> all >>>> drm_kms_helper_poll_disable() calls. >>>> >>>> #regzbot ^introduced a4e771729a51 >>>> >>>> ciao >>>> Janne >>> >>> Dear Janne: >>> >>> I agree with you like I mentioned on last letter. >>> Thanks for your time. >>> >>> >>> Dear Dmitry: >>> >>> Is there anything else I can do? >>> Looking forward to your reply. >> >> If it is a common consensus, I'm fine with your approach. >> > Dear Dmitry: > > Ok.Thanks for your reply. > > Best regards! > >
