Re: Commit 8a7bf7510d1f ("USB: serial: pl2303: amend and tighten type detection") broke pl2303 driver for my adapter

On Thu, Jul 29, 2021 at 3:02 AM Johan Hovold [off-list ref] wrote:

On Tue, Jul 27, 2021 at 05:00:20PM -0700, Vasily Khoruzhick wrote:

quoted

Hey,

My PL2303 adapter isn't working after I upgraded to 5.13.

Looks like the culprit is commit 8a7bf7510d1f ("USB: serial: pl2303:
amend and tighten type detection").

It used to work fine in 5.12.x.

Now it fails like this:

[246872.298632] usb 1-1: new full-speed USB device number 14 using xhci_hcd
[246872.440065] usb 1-1: New USB device found, idVendor=067b,
idProduct=23c3, bcdDevice= 3.05
[246872.440079] usb 1-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[246872.440085] usb 1-1: Product: USB-Serial Controller
[246872.440089] usb 1-1: Manufacturer: Prolific Technology Inc.
[246872.440093] usb 1-1: SerialNumber: CMA>b103Y23
[246872.445098] pl2303 1-1:1.0: pl2303 converter detected
[246872.445114] pl2303 1-1:1.0: unknown device type, please report to
linux-usb@vger.kernel.org

Thanks for the report. Can you please post the output of lsusb -v for
this device?

Here it is:

Bus 001 Device 024: ID 067b:23c3 Prolific Technology, Inc. USB-Serial
Controller
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x067b Prolific Technology, Inc.
  idProduct          0x23c3
  bcdDevice            3.05
  iManufacturer           1 Prolific Technology Inc.
  iProduct                2 USB-Serial Controller
  iSerial                 3 CMA>b103Y23
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0027
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower              100mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           3
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x000a  1x 10 bytes
        bInterval               1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0

quoted

Any ideas on how to fix it properly? Should I send a patch that
handles bcdDevice == 0x305 and returns TYPE_HX for it from
pl2303_detect_type()?

The device id indicates that this is in fact a PL2303GT so we may need
to amend the HXN type detection.

What's the difference between HX and HXN?

Johan