[BRLTTY] Baum filtering still too open?

[Dave Mielke]

[quoted lines by Samuel Thibault on 2024/11/22 at 01:05 +0100]

>For the NLS eReader Zoomax, we can see in udev:
>
>ENV{PRODUCT}=="1a86/7523/*", ATTRS{idVendor}=="1a40", ATTRS{idProduct}=="0101", ENV{BRLTTY_BRAILLE_DRIVER}="bm", GOTO="brltty_usb_run"
>
>In https://bugs.launchpad.net/ubuntu/+source/brltty/+bug/1958224/comments/46
>Alessandro Astone is surprised that ENV{PRODUCT} could be different
>from ATTRS{idVendor} and ATTRS{idProduct}.

The first one matches the braille device itself, whereas the second and third match the device's parent (i.e. the internal hub). Note: ATTRS != ATTR

>My guess is that we are here matching the usb device and the usb hub on which it is connected.

Yes.

>But the vendor/product ids don't really seem specific to Baum?

It isn't, but it does use the Baum protocol hence, in brltty, the Baum driver is used.

>One could very well plug a QinHeng Electronics HL-340 USB-Serial adapter (1a86/7523) on a Terminus Technology Inc. 4-Port HUB (1a40/0101).

Yes, one could. It'd have to be exactly that combination, though, which, at the time, I deemed rare enough. The device needs to be detected without special action because the US government (NLS stands for National Library Service) gives the device way (actually, lends it) to lots of people whom we daren't assume to be technically skilled.

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