Re: [PATCH v10 0/6] Re-introduce TX FIFO resize for larger EP bursting

[Ferry Toth]

Op 21-08-2021 om 04:57 schreef Thinh Nguyen:
> Pavel Hofman wrote:
> > Dne 19. 08. 21 v 22:10 Ferry Toth napsal(a):
> > > Hi
> > >
> > > Op 19-08-2021 om 09:51 schreef Pavel Hofman:
> > > > Hi,
> > > >
> > > > Dne 18. 08. 21 v 21:07 Ferry Toth napsal(a):
> > > > > Hi,
> > > > >
> > > > > Op 18-08-2021 om 00:00 schreef Ferry Toth:
> > > > > > Hi,
> > > > > >
> > > > > > Op 16-08-2021 om 07:18 schreef Felipe Balbi:
> > > > > > > Hi,
> > > > > > >
> > > > > > > Ferry Toth <fntoth@xxxxxxxxx> writes:
> > > > > > > > > Ferry Toth <fntoth@xxxxxxxxx> writes:
> > > > > > > > > > > > > Ferry Toth <fntoth@xxxxxxxxx> writes:
> > > > > > > > > > > > > > > > > > Hardware name: Intel Corporation Merrifield/BODEGA BAY,
> > > > > > > > > > > > > > > > > > BIOS 542
> > > > > > > > > > > > > > > > > > 2015.01.21:18.19.48
> > > > > > > > > > > > > > > > > > RIP: 0010:0x500000000
> > > > > > > > > > > > > > > > > > Code: Unable to access opcode bytes at RIP 0x4ffffffd6.
> > > > > > > > > > > > > > > > > > RSP: 0018:ffffa4d00045fc28 EFLAGS: 00010046
> > > > > > > > > > > > > > > > > > RAX: 0000000500000000 RBX: ffff8cd546aed200 RCX:
> > > > > > > > > > > > > > > > > > 0000000000000000
> > > > > > > > > > > > > > > > > > RDX: 0000000000000000 RSI: ffff8cd547bfcae0 RDI:
> > > > > > > > > > > > > > > > > > ffff8cd546aed200
> > > > > > > > > > > > > > > > > > RBP: ffff8cd547bfcae0 R08: 0000000000000000 R09:
> > > > > > > > > > > > > > > > > > 0000000000000001
> > > > > > > > > > > > > > > > > > R10: ffff8cd541fd28c0 R11: 0000000000000000 R12:
> > > > > > > > > > > > > > > > > > ffff8cd547342828
> > > > > > > > > > > > > > > > > > R13: ffff8cd546aed248 R14: 0000000000000000 R15:
> > > > > > > > > > > > > > > > > > ffff8cd548b1d000
> > > > > > > > > > > > > > > > > > FS:  0000000000000000(0000) GS:ffff8cd57e200000(0000)
> > > > > > > > > > > > > > > > > > knlGS:0000000000000000
> > > > > > > > > > > > > > > > > > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > > > > > > > > > > > > > > > > CR2: 0000000500000000 CR3: 000000000311e000 CR4:
> > > > > > > > > > > > > > > > > > 00000000001006f0
> > > > > > > > > > > > > > > > > > Call Trace:
> > > > > > > > > > > > > > > > > >          ? dwc3_remove_requests.constprop.0+0x14d/0x170
> > > > > > > > > > > > > > > > > >          ? __dwc3_gadget_ep_disable+0x7a/0x160
> > > > > > > > > > > > > > > > > >          ? dwc3_gadget_ep_disable+0x3d/0xd0
> > > > > > > > > > > > > > > > > >          ? usb_ep_disable+0x1c/0x
> > > > > > > > > > > > > > > > > >          ? u_audio_stop_capture+0x79/0x120 [u_audio]
> > > > > > > > > > > > > > > > > >          ? afunc_set_alt+0x73/0x80 [usb_f_uac2]
> > > > > > > > > > > So this is triggered by a SetInterface request...
> > > > > > > > > > >
> > > > > > > > > > > > > > > > > >          ? composite_setup+0x224/0x1b90 [libcomposite]
> > > > > > > > > > > > > > > > > >          ? __dwc3_gadget_kick_transfer+0x160/0x400
> > > > > > > > > > > > > > > > > >          ? dwc3_gadget_ep_queue+0xf3/0x1a0
> > > > > > > > > > > > > > > > > >          ? configfs_composite_setup+0x6b/0x90
> > > > > > > > > > > > > > > > > > [libcomposite]
> > > > > > > > > > > > > > > > > >          ? configfs_composite_setup+0x6b/0x90
> > > > > > > > > > > > > > > > > > [libcomposite]
> > > > > > > > > > > > > > > > > >          ? dwc3_ep0_interrupt+0x459/0xa40
> > > > > > > > > > > > > > > > > >          ? dwc3_thread_interrupt+0x8ee/0xf40
> > > > > > > > > > > > > > > > > >          ? __schedule+0x235/0x6c0
> > > > > > > > > > > > > > > > > >          ? disable_irq_nosync+0x10/0x10
> > > > > > > > > > > > > > > > > >          ? irq_thread_fn+0x1b/0x60
> > > > > > > > > > > > > > > > > >          ? irq_thread+0xc0/0x160
> > > > > > > > > > > > > > > > > >          ? irq_thread_check_affinity+0x70/0x70
> > > > > > > > > > > > > > > > > >          ? irq_forced_thread_fn+0x70/0x70
> > > > > > > > > > > > > > > > > >          ? kthread+0x122/0x140
> > > > > > > > > > > > > > > > > >          ? set_kthread_struct+0x40/0x40
> > > > > > > > > > > > > > > > > >          ? ret_from_fork+0x22/0x30
> > > > > > > > > > > > > > > > > Do you mind enabling dwc3 traces and collecting them?
> > > > > > > > > > > > > > > > > Trying to figure
> > > > > > > > > > > > > > > > > out how we got here.
> > > > > > > > > > > > > > > > I'll try if I can get the same error by booting with USB
> > > > > > > > > > > > > > > > in host mode
> > > > > > > > > > > > > > > > and then switch to device mode. If so I can enable traces
> > > > > > > > > > > > > > > > and collect as
> > > > > > > > > > > > > > > > you explained me before.
> > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > I'll try before monday, as then I fly for a holiday and
> > > > > > > > > > > > > > > > will not be
> > > > > > > > > > > > > > > > available before rc5.
> > > > > > > > > > > > > > > you can enable all of those with kernel cmdline :-)
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > https://urldefense.com/v3/__https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html__;!!A4F2R9G_pg!PZHOWnH3HDs-9a9bz4KLDShZpsubSfG84fu3wEZyK4Q_Wvv2lhHKuk7LJpWPAPch0qja$
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > you need ftrace_dump_on_oops=1 and also need the correct
> > > > > > > > > > > > > > > options on
> > > > > > > > > > > > > > > trace_buf_size and trace_event.
> > > > > > > > > > > > > > On Edison-Arduino I have a switch to go to device mode,
> > > > > > > > > > > > > > after which
> > > > > > > > > > > > > > udev triggers a script configure gadgets through configfs.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > I tried to log following these instructions:
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > https://urldefense.com/v3/__https://www.kernel.org/doc/html/latest/driver-api/usb/dwc3.html*reporting-bugs__;Iw!!A4F2R9G_pg!PZHOWnH3HDs-9a9bz4KLDShZpsubSfG84fu3wEZyK4Q_Wvv2lhHKuk7LJpWPAG64agnA$
> > > > > > > > > > > > > > <https://urldefense.com/v3/__https://www.kernel.org/doc/html/latest/driver-api/usb/dwc3.html*reporting-bugs__;Iw!!A4F2R9G_pg!PZHOWnH3HDs-9a9bz4KLDShZpsubSfG84fu3wEZyK4Q_Wvv2lhHKuk7LJpWPAG64agnA$
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > Unfortunately the kernel crashes so badly I can not get to
> > > > > > > > > > > > > > the ` cp
> > > > > > > > > > > > > > /t/trace /root/trace.txt` line (after a while the watchdog
> > > > > > > > > > > > > > kicks).
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > What to do next?
> > > > > > > > > > > > > Pass ftrace_dump_on_oops to kernel cmdline.
> > > > > > > > > > > > No sure if I did this right, on oops everything is pushed to
> > > > > > > > > > > > console
> > > > > > > > > > > > (115k2 serial), I hope nothing essential is lost.
> > > > > > > > > > > >
> > > > > > > > > > > > I copied the screen buffer to file see attached.
> > > > > > > > > > > Thank you, I bet it took quite a some time :-) Anyway, looking at
> > > > > > > > > > > the logs around Set Interface requests, we can track every
> > > > > > > > > > > endpoint
> > > > > > > > > > > that's disabled. I'll take a guess and assume we're failing at
> > > > > > > > > > > the last
> > > > > > > > > > > Set Interface, that means we should have something odd with
> > > > > > > > > > > ep6in, but
> > > > > > > > > > > everything looks fine in the trace output:
> > > > > > > > > > >
> > > > > > > > > > > [   75.823107] irq/14-d-596       0d... 42789194us :
> > > > > > > > > > > dwc3_gadget_ep_enable: ep6in: mps 192/346 streams 16 burst 0
> > > > > > > > > > > ring 0/0 flags E:swbp:<
> > > > > > > > > > > [   75.835472] irq/14-d-596       0d... 42789198us :
> > > > > > > > > > > dwc3_alloc_request: ep6in: req 0000000002c71409 length 0/0 zsI
> > > > > > > > > > > ==> 0
> > > > > > > > > > > [   75.846416] irq/14-d-596       0d... 42789202us :
> > > > > > > > > > > dwc3_ep_queue: ep6in: req 0000000002c71409 length 0/192 zsI
> > > > > > > > > > > ==> -115
> > > > > > > > > > > [   75.857360] irq/14-d-596       0d... 42789204us :
> > > > > > > > > > > dwc3_alloc_request: ep6in: req 00000000a324f5d0 length 0/0 zsI
> > > > > > > > > > > ==> 0
> > > > > > > > > > > [   75.868301] irq/14-d-596       0d... 42789206us :
> > > > > > > > > > > dwc3_ep_queue: ep6in: req 00000000a324f5d0 length 0/192 zsI
> > > > > > > > > > > ==> -115
> > > > > > > > > > > [   75.879244] irq/14-d-596       0d... 42789209us :
> > > > > > > > > > > dwc3_event: event (000020c2): ep0in: Transfer Not Ready [0]
> > > > > > > > > > > (Not Active) [Status Phase]
> > > > > > > > > > > [   75.891880] irq/14-d-596       0d... 42789211us :
> > > > > > > > > > > dwc3_prepare_trb: ep0in: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 000000001bded000 size 0 ctrl 00000c33 (HLcs:SC:status2)
> > > > > > > > > > > [   75.989131] irq/14-d-596       0d... 42789224us :
> > > > > > > > > > > dwc3_gadget_ep_cmd: ep0in: cmd 'Start Transfer' [406] params
> > > > > > > > > > > 00000000 1bded000 00000000 --> status: Successful
> > > > > > > > > > > [   76.096261] irq/14-d-596       0d... 42789272us :
> > > > > > > > > > > dwc3_event: event (0000c042): ep0in: Transfer Complete (sIL)
> > > > > > > > > > > [Status Phase]
> > > > > > > > > > > [   76.107834] irq/14-d-596       0d... 42789275us :
> > > > > > > > > > > dwc3_complete_trb: ep0out: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 000000001bded000 size 0 ctrl 00000c32 (hLcs:SC:status2)
> > > > > > > > > > > [   76.122944] irq/14-d-596       0d... 42789277us :
> > > > > > > > > > > dwc3_gadget_giveback: ep0out: req 00000000cb1bd3cd length 0/0
> > > > > > > > > > > zsI ==> 0
> > > > > > > > > > > [   76.134160] irq/14-d-596       0d... 42789280us :
> > > > > > > > > > > dwc3_prepare_trb: ep0out: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 000000001bded000 size 8 ctrl 00000c23 (HLcs:SC:setup)
> > > > > > > > > > > [   76.231322] irq/14-d-596       0d... 42789292us :
> > > > > > > > > > > dwc3_gadget_ep_cmd: ep0out: cmd 'Start Transfer' [406] params
> > > > > > > > > > > 00000000 1bded000 00000000 --> status: Successful
> > > > > > > > > > > [   76.297418] kworker/-23        0d... 42789670us :
> > > > > > > > > > > dwc3_ep_queue: ep3in: req 0000000029586135 length 0/96 ZsI ==>
> > > > > > > > > > > -115
> > > > > > > > > > > [   76.308278] kworker/-23        0d... 42789695us :
> > > > > > > > > > > dwc3_prepare_trb: ep3in: trb 00000000b81213d6 (E1:D0) buf
> > > > > > > > > > > 0000000003b7a800 size 96 ctrl 00000811 (Hlcs:sC:normal)
> > > > > > > > > > > [   76.395294] kworker/-23        0d... 42789707us :
> > > > > > > > > > > dwc3_gadget_ep_cmd: ep3in: cmd 'Update Transfer' [60007]
> > > > > > > > > > > params 00000000 00000000 00000000 --> status: Successful
> > > > > > > > > > > [   76.471900] irq/14-d-596       0d... 42789842us :
> > > > > > > > > > > dwc3_event: event (0000c040): ep0out: Transfer Complete (sIL)
> > > > > > > > > > > [Setup Phase]
> > > > > > > > > > > [   76.489308] irq/14-d-596       0d... 42789845us :
> > > > > > > > > > > dwc3_ctrl_req: Set Interface(Intf = 5, Alt.Setting = 0)
> > > > > > > > > > > [   76.505650] irq/14-d-596       0d... 42789851us :
> > > > > > > > > > > dwc3_ep_dequeue: ep6in: req 0000000002c71409 length 0/192 zsI
> > > > > > > > > > > ==> -115
> > > > > > > > > > > [   76.523315] irq/14-d-596       0d... 42789854us :
> > > > > > > > > > > dwc3_gadget_giveback: ep6in: req 0000000002c71409 length 0/192
> > > > > > > > > > > zsI ==> -104
> > > > > > > > > > > [   76.541427] irq/14-d-596       0d... 42789857us :
> > > > > > > > > > > dwc3_free_request: ep6in: req 0000000002c71409 length 0/192
> > > > > > > > > > > zsI ==> -104
> > > > > > > > > > > [   76.559267] irq/14-d-596       0d... 42789859us :
> > > > > > > > > > > dwc3_ep_dequeue: ep6in: req 00000000a324f5d0 length 0/192 zsI
> > > > > > > > > > > ==> -115
> > > > > > > > > > > [   76.576937] irq/14-d-596       0d... 42789861us :
> > > > > > > > > > > dwc3_gadget_giveback: ep6in: req 00000000a324f5d0 length 0/192
> > > > > > > > > > > zsI ==> -104
> > > > > > > > > > > [   76.595046] irq/14-d-596       0d... 42789862us :
> > > > > > > > > > > dwc3_free_request: ep6in: req 00000000a324f5d0 length 0/192
> > > > > > > > > > > zsI ==> -104
> > > > > > > > > > > [   76.612892] irq/14-d-596       0d... 42789865us :
> > > > > > > > > > > dwc3_gadget_ep_disable: ep6in: mps 192/346 streams 16 burst 0
> > > > > > > > > > > ring 0/0 flags E:swbp:<
> > > > > > > > > > > [   76.665535] irq/14-d-596       0d... 42789873us :
> > > > > > > > > > > dwc3_event: event (000020c2): ep0in: Transfer Not Ready [0]
> > > > > > > > > > > (Not Active) [Status Phase]
> > > > > > > > > > > [   76.684716] irq/14-d-596       0d... 42789875us :
> > > > > > > > > > > dwc3_prepare_trb: ep0in: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 000000001bded000 size 0 ctrl 00000c33 (HLcs:SC:status2)
> > > > > > > > > > > [   76.819195] irq/14-d-596       0d... 42789886us :
> > > > > > > > > > > dwc3_gadget_ep_cmd: ep0in: cmd 'Start Transfer' [406] params
> > > > > > > > > > > 00000000 1bded000 00000000 --> status: Successful
> > > > > > > > > > > [   76.926324] irq/14-d-596       0d... 42789930us :
> > > > > > > > > > > dwc3_event: event (0000c042): ep0in: Transfer Complete (sIL)
> > > > > > > > > > > [Status Phase]
> > > > > > > > > > > [   76.937892] irq/14-d-596       0d... 42789933us :
> > > > > > > > > > > dwc3_complete_trb: ep0out: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 000000001bded000 size 0 ctrl 00000c32 (hLcs:SC:status2)
> > > > > > > > > > > [   76.953003] irq/14-d-596       0d... 42789935us :
> > > > > > > > > > > dwc3_gadget_giveback: ep0out: req 00000000cb1bd3cd length 0/0
> > > > > > > > > > > zsI ==> 0
> > > > > > > > > > > [   76.964217] irq/14-d-596       0d... 42789938us :
> > > > > > > > > > > dwc3_prepare_trb: ep0out: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 000000001bded000 size 8 ctrl 00000c23 (HLcs:SC:setup)
> > > > > > > > > > > [   77.061379] irq/14-d-596       0d... 42789950us :
> > > > > > > > > > > dwc3_gadget_ep_cmd: ep0out: cmd 'Start Transfer' [406] params
> > > > > > > > > > > 00000000 1bded000 00000000 --> status: Successful
> > > > > > > > > > > [   77.168595] irq/14-d-596       0d... 42790509us :
> > > > > > > > > > > dwc3_event: event (0000c040): ep0out: Transfer Complete (sIL)
> > > > > > > > > > > [Setup Phase]
> > > > > > > > > > > [   77.180159] irq/14-d-596       0d... 42790512us :
> > > > > > > > > > > dwc3_ctrl_req: Get String Descriptor(Index = 18, Length = 255)
> > > > > > > > > > > [   77.190578] irq/14-d-596       0d... 42790537us :
> > > > > > > > > > > dwc3_prepare_trb: ep0in: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 0000000003b68000 size 36 ctrl 00000c53 (HLcs:SC:data)
> > > > > > > > > > > [   77.287648] irq/14-d-596       0d... 42790550us :
> > > > > > > > > > > dwc3_gadget_ep_cmd: ep0in: cmd 'Start Transfer' [406] params
> > > > > > > > > > > 00000000 1bded000 00000000 --> status: Successful
> > > > > > > > > > > [   77.333107] irq/14-d-596       0d... 42790557us :
> > > > > > > > > > > dwc3_event: event (000010c2): ep0in: Transfer Not Ready [0]
> > > > > > > > > > > (Not Active) [Data Phase]
> > > > > > > > > > > [   77.407223] irq/14-d-596       0d... 42790575us :
> > > > > > > > > > > dwc3_event: event (000090c2): ep0in: Transfer Not Ready [0]
> > > > > > > > > > > (Active) [Data Phase]
> > > > > > > > > > > [   77.480985] irq/14-d-596       0d... 42790588us :
> > > > > > > > > > > dwc3_event: event (0000c042): ep0in: Transfer Complete (sIL)
> > > > > > > > > > > [Data Phase]
> > > > > > > > > > > [   77.492376] irq/14-d-596       0d... 42790590us :
> > > > > > > > > > > dwc3_complete_trb: ep0out: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 0000000003b68000 size 0 ctrl 00000c52 (hLcs:SC:data)
> > > > > > > > > > > [   77.507221] irq/14-d-596       0d... 42790595us :
> > > > > > > > > > > dwc3_gadget_giveback: ep0out: req 00000000cb1bd3cd length
> > > > > > > > > > > 36/36 ZsI ==> 0
> > > > > > > > > > > [   77.518609] irq/14-d-596       0d... 42790597us :
> > > > > > > > > > > dwc3_event: event (000020c0): ep0out: Transfer Not Ready [0]
> > > > > > > > > > > (Not Active) [Status Phase]
> > > > > > > > > > > [   77.531332] irq/14-d-596       0d... 42790598us :
> > > > > > > > > > > dwc3_prepare_trb: ep0out: trb 000000004c0ae319 (E0:D0) buf
> > > > > > > > > > > 000000001bded000 size 0 ctrl 00000c43 (HLcs:SC:status3)
> > > > > > > > > > > [   77.628669] irq/14-d-596       0d... 42790609us :
> > > > > > > > > > > dwc3_gadget_ep_cmd: ep0out: cmd 'Start Transfer' [406] params
> > > > > > > > > > > 00000000 1bded000 00000000 --> status: Successful
> > > > > > > > > > >
> > > > > > > > > > > Do you mind adding a few prints in dwc3_remove_requests to
> > > > > > > > > > > tell us which
> > > > > > > > > > > endpoint is being processed? Then we'll know for sure which
> > > > > > > > > > > one caused
> > > > > > > > > > > the crash.
> > > > > > > > > > I wouldn't mind but am leaving on a holiday, won't have time
> > > > > > > > > > until 6 aug.
> > > > > > > > > not a problem, we'll still be here when you're back :-)
> > > > > > > > Well, let's go then :-)
> > > > > > > >
> > > > > > > > To get back in the mood I have retested 5.13.0, 5.14.0-rc1,
> > > > > > > > 5.14.0-rc2
> > > > > > > > and 5.14.0-rc5.
> > > > > > > >
> > > > > > > > I find that 5.13.0 works fine, and the issue starts from 5.14.0-rc1.
> > > > > > > That's great finding. We have a bisection point. There are a total of
> > > > > > > 13764 commits between v5.13 and v5.14-rc1
> > > > > > >
> > > > > > >      $ git rev-list  --count v5.13..v5.14-rc1
> > > > > > >      13764
> > > > > > >
> > > > > > > git bisect should find the offending commit in at most 14 tries.
> > > > > > > That's
> > > > > > > not too bad.
> > > > > > I correctly guesstimated that the problem got introduced by the usb
> > > > > > merge 79160a60
> > > > > >
> > > > > > "Merge tag 'usb-5.14-rc1' of
> > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb"
> > > > > >
> > > > > > 116 commits(7 bisects).
> > > > > >
> > > > > > 24f779dac8f3efb9629adc0e486914d93dc45517 is the first bad commit
> > > > > >
> > > > > > "usb: gadget: f_uac2/u_audio: add feedback endpoint support"
> > > > > >
> > > > > > Ruslan's 3 patches are related to each other so I reverted all
> > > > > > three 24f779da...e89bb428 and applied the reverts to rc1.
> > > > > >
> > > > > > I can confirm this indeed resolves the problem in rc1.
> > > > > >
> > > > > > Is late now, tomorrow evening I will apply the reverts to rc6.
> > > > >
> > > > > With these reverts rc6 works fine as well.
> > > > >
> > > > > So, where do we go from here?
> > > >
> > > > I know the patches have been tested on dwc2 (by me and others).  I do
> > > > not know if Ruslan or Jerome tested them on dwc3 but probably not.
> > > > Ruslan has talked about RPi (my case too) and BeagleboneBlack, both
> > > > with dwc2. Perhaps the dwc2 behaves a bit differently than dwc3?
> > > >
> > > > The patches add a new EP-IN for async feedback. I am sorry I have not
> > > > followed your long thread (it started as unrelated to uac). Does the
> > > > problem appear with f_uac1 or f_uac2? Please how have you reached the
> > > > above problem?
> > >
> > > I'm sorry too. I first believed the issue was related to the patch
> > > mentioned in the subject line.
> > >
> > > The problem appaers with f_uac2. I bost Edison_Arduino board in host
> > > mode (there is a switch allowing to select host/device mode). When
> > > flipping the switch to device mode udev run a script:
> > > But as I am using configfs (excerpt follows) and just disabling the
> > > last 2 line resolves the issue, I'm guessing uac2 is the issue. Or
> > > exceeding the available resources.
> > >
> > > # Create directory structure
> > > mkdir "${GADGET_BASE_DIR}"
> > > cd "${GADGET_BASE_DIR}"
> > > mkdir -p configs/c.1/strings/0x409
> > > mkdir -p strings/0x409
> > >
> > > # Serial device
> > > mkdir functions/gser.usb0
> > > ln -s functions/gser.usb0 configs/c.1/
> > > ###
> > >
> > > # Ethernet device
> > > mkdir functions/eem.usb0
> > > echo "${DEV_ETH_ADDR}" > functions/eem.usb0/dev_addr
> > > echo "${HOST_ETH_ADDR}" > functions/eem.usb0/host_addr
> > > ln -s functions/eem.usb0 configs/c.1/
> > >
> > > # Mass Storage device
> > > mkdir functions/mass_storage.usb0
> > > echo 1 > functions/mass_storage.usb0/stall
> > > echo 0 > functions/mass_storage.usb0/lun.0/cdrom
> > > echo 0 > functions/mass_storage.usb0/lun.0/ro
> > > echo 0 > functions/mass_storage.usb0/lun.0/nofua
> > > echo "${USBDISK}" > functions/mass_storage.usb0/lun.0/file
> > > ln -s functions/mass_storage.usb0 configs/c.1/
> > >
> > > # UAC2 device
> > > mkdir functions/uac2.usb0
> > > ln -s functions/uac2.usb0 configs/c.1
> > > ....
> >
> > As you say, could perhaps the reason be that the extra EP-IN added in
> > those patches (previously 1, now 2 with the default config you use)
> > exceeds your EP-IN max count or available fifos somehow?  You have a
> > number of functions initialized. If you change the load order of the
> > functions, do you get the error later with a different function? Just
> > guessing...
> >
> > You should be able to switch the default async EP-OUT (which configures
> > the new feedback EP-IN ) to adaptive EP-OUT (which requires no feedback
> > EP) with c_sync=8 parameter of f_uac2.
> >
> > https://urldefense.com/v3/__https://elixir.bootlin.com/linux/v5.14-rc6/source/drivers/usb/gadget/function/f_uac2.c*L47__;Iw!!A4F2R9G_pg!PZHOWnH3HDs-9a9bz4KLDShZpsubSfG84fu3wEZyK4Q_Wvv2lhHKuk7LJpWPAHQ6Lj4y$
> >
> > https://urldefense.com/v3/__https://elixir.bootlin.com/linux/v5.14-rc6/source/drivers/usb/gadget/function/f_uac2.c*L830__;Iw!!A4F2R9G_pg!PZHOWnH3HDs-9a9bz4KLDShZpsubSfG84fu3wEZyK4Q_Wvv2lhHKuk7LJpWPAC7mfgo7$
> >
> > https://urldefense.com/v3/__https://elixir.bootlin.com/linux/v5.14-rc6/source/include/uapi/linux/usb/ch9.h*L453__;Iw!!A4F2R9G_pg!PZHOWnH3HDs-9a9bz4KLDShZpsubSfG84fu3wEZyK4Q_Wvv2lhHKuk7LJpWPANdeuGIx$
> >
> > Does that fix the problem?
>
> Hi Pavel,
>
> I took a look at 24f779dac8f3 ("usb: gadget: f_uac2/u_audio: add
> feedback endpoint support") that Ferry reported the issue from
> bisection. I see at least a couple problems in the new UAC2 changes.
>
> 1) usb_ep_dequeue() is asynchronous. Don't free requests before the
> controller driver give them back.
>
> 2) Did you test with SuperSpeed? I don't see companion descriptor.
>
> Please fix them.

Given it's late in the cycle I agree with Andy it would be best to 
revert the series now.

I will be happy to test on dwc3 when a fixed series arrives.

> Thanks,
> Thinh