Comment 3 for bug 1967493

Hi,
thanks for testing this out,
from the attachment it looks like your pl2303 does not work with the new device detection algorithm in 5.13 kernel:

https://kernel.ubuntu.com/git/ubuntu/ubuntu-impish.git/tree/drivers/usb/serial/pl2303.c#n421
Which can only handle devices with bcdUSB 1.10 and 2.00

However yours is 1.01:
Bus 001 Device 004: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 1.01
  bDeviceClass 0
  bDeviceSubClass 0
  bDeviceProtocol 0
  bMaxPacketSize0 64
  idVendor 0x067b Prolific Technology, Inc.
  idProduct 0x2303 PL2303 Serial Port
  bcdDevice 3.00

I would suggest you to give the latest mainline kernel [1] a try to see if this issue exist with the latest kernel, you will find instructions here [2].

If the issue still exist, please report this issue to <email address hidden>, indicating the kernel version and attach the lsusb -v output for this device.

Thanks!

[1] https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.18-rc5/
[2] https://wiki.ubuntu.com/Kernel/MainlineBuilds#How_do_I_install_an_upstream_kernel.3F