[Bug 1931684] Re: cdc_acm: acm_port_activate - usb_submit_urb(ctrl irq) failed

[Matthias Kuntze]

I did an upgrade from kernel 5.4.0-74-generic to 5.4.0-77-generic and
the problem disappeared.

$ stty -F /dev/ttyACM0
speed 57600 baud; line = 0;
eof = ^A; min = 1; time = 0;
-brkint -icrnl -imaxbel
-opost -onlcr
-icanon -echo -echoe

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Title:
  cdc_acm: acm_port_activate - usb_submit_urb(ctrl irq) failed

Status in intel-microcode package in Ubuntu:
  Confirmed
Status in linux package in Ubuntu:
  Confirmed
Status in linux-firmware package in Ubuntu:
  Confirmed

Bug description:
  Ubuntu 18.04.5 LTS
  Recently, after kernel update 4.15.0.144 (didn't know about the case yet), i can't open serial ports on USB CDC devices (STM32 Virtual COMs in my case).

  using simple cat command (with or without sudo):
  $ sudo cat /dev/ttyACM1 
  cat: /dev/ttyACM1: Input/output error

  or some serial programs:
  Failed to connect to /dev/ttyACM1 : [Errno 5] could not open port /dev/ttyACM1: [Errno 5] Input/output error: '/dev/ttyACM1'

  dmesg:
  [ 3295.718270] cdc_acm 1-2:1.0: ttyACM1: USB ACM device
  [ 3302.508356] cdc_acm 1-2:1.0: acm_port_activate - usb_submit_urb(ctrl irq) failed
  [ 3302.508940] cdc_acm 1-2:1.0: acm_port_activate - usb_submit_urb(ctrl irq) failed

  When i try spamming commands while plugging the device in, i am
  sometimes able to open the port (might be the clue).

  When i booted in ubuntu advanced mode to 4.15.0.143 kernel, everything
  started to work normally.

  Also tried HWE stack with 5.4.0.74 kernel, but the bug was also
  present there.

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