Re: pl2303 converter - unknown device type

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Aug 05, 2025 at 07:07:03AM +0000, Ulrich Stoehlker wrote:
> Dear all,
> 
> I have a Multi-Channel-Analyzer (MCA) interfaced via usb.
> This device cannot be used on more recent kernels.
> I get the following error message:
> 
> [663822.490455] usb 1-3: new high-speed USB device number 17 using xhci_hcd
> [663822.616495] usb 1-3: New USB device found, idVendor=0557, idProduct=2008, bcdDevice= 0.01
> [663822.616501] usb 1-3: New USB device strings: Mfr=0, Product=0, SerialNumber=0
> [663822.682309] usbcore: registered new interface driver usbserial_generic
> [663822.682326] usbserial: USB Serial support registered for generic
> [663822.686383] usbcore: registered new interface driver pl2303
> [663822.686402] usbserial: USB Serial support registered for pl2303
> [663822.686423] pl2303 1-3:1.0: pl2303 converter detected
> [663822.686431] pl2303 1-3:1.0: unknown device type, please report to linux-usb@vger.kernel.org
> 
> Linux host1 6.8.0-64-generic #67~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Jun 24 15:19:46 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

6.8.0 is over a year old.  Can you try a more modern kernel release?

> But it works with older kernels:
> Linux host2 5.10.103-v7+ #1529 SMP Tue Mar 8 12:21:37 GMT 2022 armv7l GNU/Linux
> 
> Would it be possible to correct this problem!?

Can you provide the output of 'lsusb -v' with this device plugged in?
But again, please try a newer kernel version, 6.8.0 is very very old and
obsolete and not supported at all by the kernel community.

thanks,

greg k-h