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

From: Ferry Toth
Date: Sun Aug 15 2021 - 16:57:33 EST


Hi,

Op 26-07-2021 om 07:57 schreef Felipe Balbi:
Hi,

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://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html

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://www.kernel.org/doc/html/latest/driver-api/usb/dwc3.html#reporting-bugs <https://www.kernel.org/doc/html/latest/driver-api/usb/dwc3.html#reporting-bugs>

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.

With 5.14.0-rc5 the problem seems worse (or different?), and just disabling uac2 gadget does not prevent the crash. Even disabling gser and mass_storage.usb0 as well there is still a crash.

Now I'm not sure how to proceed. Bisect rc1? Or focus on rc5 (rc6?)?

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
Right, either there's an actual bug in uac2, or we're running out of
FIFO space.