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 linux- u...@vger.kernel.org, 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 ** Changed in: linux-signed-hwe-5.13 (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-signed-hwe-5.13 in Ubuntu. https://bugs.launchpad.net/bugs/1967493 Title: pl2303 serial adapter not recognized Status in linux-signed-hwe-5.13 package in Ubuntu: Incomplete Bug description: Hi After upgrading the Linux kernel from 5.11.0-27 to 5.13.0-37 a device that uses a pl2303 usb serial chip no longer works. This seems very similar to bug 1959110, and according to that it should be fixed, but somehow it's not. # uname -a Linux GAU233333LD04 5.13.0-37-generic #42~20.04.1-Ubuntu SMP Tue Mar 15 15:44:28 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux # journalctl -b -k -g pl2303 -o cat usbcore: registered new interface driver pl2303 usbserial: USB Serial support registered for pl2303 pl2303 1-12:1.0: pl2303 converter detected pl2303 1-12:1.0: unknown device type, please report to linux-...@vger.kernel.org # udevadm info /sys/devices/pci0000:00/0000:00:14.0/usb1/1-12/1-12:1.0 P: /devices/pci0000:00/0000:00:14.0/usb1/1-12/1-12:1.0 L: 0 E: DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-12/1-12:1.0 E: DEVTYPE=usb_interface E: PRODUCT=67b/2303/300 E: TYPE=0/0/0 E: INTERFACE=255/0/0 E: MODALIAS=usb:v067Bp2303d0300dc00dsc00dp00icFFisc00ip00in00 E: SUBSYSTEM=usb E: USEC_INITIALIZED=56177916 E: ID_VENDOR_FROM_DATABASE=Prolific Technology, Inc. E: ID_MODEL_FROM_DATABASE=PL2303 Serial Port E: ID_PATH=pci-0000:00:14.0-usb-0:12:1.0 E: ID_PATH_TAG=pci-0000_00_14_0-usb-0_12_1_0 E: ID_MM_TTY_MANUAL_SCAN_ONLY=1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.13/+bug/1967493/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
