[Bug 1958224] Re: brltty claiming cp210x devices on 22.04

[Samuel thibault]

> aren't the identifiers in ENV{PRODUCT} already idVendor/idProduct?

I don't know the details. From what I gather from the upstream source
code, this device has a special rule to appear like this in the udev
file:

Drivers/Braille/Baum/braille.c:

    { /* NLS eReader Zoomax (20 cells) */
      .vendor=0X1A86, .product=0X7523,
      .parentVendor=0X1A40, .parentProduct=0X0101,

Perhaps something like 1A86/7523 plugged on 1A40/0101. That being said
it seems like both are generic ids, and the combination of them is not
really specific to Baum devices, since one could very well plug a
QinHeng Electronics HL-340 USB-Serial adapter on a Terminus Technology
Inc. 4-Port HUB.

I have opened the question on
https://brltty.app/pipermail/brltty/2024-November/020445.html

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Title:
  brltty claiming cp210x devices on 22.04

Status in brltty package in Ubuntu:
  Fix Released
Status in brltty source package in Jammy:
  Fix Released
Status in brltty package in Debian:
  Confirmed

Bug description:
  * Impact

  The brltty udev rules are claiming generic devices IDs which makes
  some other devices like Arduino cards not able to interact with the
  serial port anymore

  * Test Case

  Try to use an Arduino over a cp210x or FTDI serial port, it should be
  able to talk to the computer

  - upgrades from focal/impish to the SRU version should have no
  question and no /etc/udev/rules.d/86-brltty-usbgeneric.rules generated

  - upgrades from brltty 6.4-4ubuntu2
  1. if a device matching the IDs 0403:6001 / 10C4:EA60 / 10C4:EA80 is connectect at the time of the upgrade it should prompt with the debconf question
  1.a if the answer is yes, /etc/udev/rules.d/86-brltty-usbgeneric.rules should be generated
  1.b if the answer is no, /etc/udev/rules.d/86-brltty-usbgeneric.rules not installed

  2. if no matching device is connected
  there should be no debconf question nor /etc/udev/rules.d/86-brltty-usbgeneric.rules generated

  - installing brltty when it was not installed
  no question and no config generated

  * Regression potential

  If the debconf logic is wrong users could be prompted with the
  question when not needed or not prompted when they should. If the udev
  rules was incorrect or wrongly installed it could lead to have brltty
  not starting when it should

  -------------------

  Distributor ID:	Ubuntu
  Description:	Ubuntu Jammy Jellyfish (development branch)
  Release:	22.04
  Codename:	jammy
  brltty:  Installed: 6.4-2ubuntu1

   brltty appears once again to be claiming cp210x devices with the
  vendor/product ID of:

  idVendor=10c4, idProduct=ea60

  Example dmesg output:
    999.215968] usb 3-6.3: New USB device found, idVendor=10c4, idProduct=ea60, bcdDevice= 1.00
  [  999.215973] usb 3-6.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
  [  999.215975] usb 3-6.3: Product: CP2103 USB to UART Bridge
  [  999.215977] usb 3-6.3: Manufacturer: Silicon Labs
  [  999.215978] usb 3-6.3: SerialNumber: 0005
  [  999.234070] usbcore: registered new interface driver usbserial_generic
  [  999.234081] usbserial: USB Serial support registered for generic
  [  999.235262] usbcore: registered new interface driver cp210x
  [  999.235272] usbserial: USB Serial support registered for cp210x
  [  999.235298] cp210x 3-6.3:1.0: cp210x converter detected
  [  999.237039] usb 3-6.3: cp210x converter now attached to ttyUSB0
  [  999.300049] input: PC Speaker as /devices/platform/pcspkr/input/input41
  [  999.807223] input: BRLTTY 6.4 Linux Screen Driver Keyboard as /devices/virtual/input/input42
  [  999.991926] usb 3-6.3: usbfs: interface 0 claimed by cp210x while 'brltty' sets config #1
  [  999.995045] cp210x ttyUSB0: cp210x converter now disconnected from ttyUSB0
  [  999.995066] cp210x 3-6.3:1.0: device disconnected

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