# uplcom.ko doesn't seem to recognize a USB-Serial adapter chip "Alcor Micro AU9720"



## Shinyatti (May 8, 2015)

Hello. Recently I bought an USB-Serial converter card that has “Alcor Micro AU9720” chip shown below (don’t ask me why I need serial cables nowadays).
http://www.kuroutoshikou.com/product/interface/serial_parallel/1s-lppcie_u/ (Sorry for Japanese, but you can see the specific sheet in the middle of the page.)

My Environment
OS            FreeBSD 10.1-release(amd64)
Hardware        hp MicroServer N57l

I googled “Alcor Micro AU9720 FreeBSD” and found uplcom.ko that mainly supports “Prolific pl2303” also does Alcor Micro AU9720 (see `man uplcom`).

What I did after installing the card into the box is adding

```
ucom_load=“YES” uplcom_load=“YES”
```
to /boot/loader.conf.

Next, the output of `dmesg | grep uplcom` is below.

```
uplcom0: <vendor 0x058f product 0x9720, class 2/0, rev 1.10/0.00, addr 2> on usbus0
uplcom0: reset failed, error=USB_ERR_STALLED
device_attach: uplcom0 attach returned 6
```
What does “reset failed, error=USB_ERR_STALLED” mean concretely? I want to know how to make it recognized correctly. I managed to find the code /usr/src/sys/dev/usb/uplcom.c defines how uplcom.ko acts like, but sadly I don’t have enough skill of C in reading this code.

In this connection, when I connect another USB-Serial Adapter that has “Prolific pl2303” chip in it, here's what `dmesg | grep uplcom` says.

```
uplcom0: <vendor 0x058f product 0x9720, class 2/0, rev 1.10/0.00, addr 2> on usbus0
uplcom0: reset failed, error=USB_ERR_STALLED
device_attach: uplcom0 attach returned 6
uplcom0: <Prolific Technology Inc. USB 2.0 To COM Device, class 0/0, rev 1.10/3.00, addr 2> on usbus2
uplcom0: at uhub4, port 3, addr 2 (disconnected)
```
It looks like uplcom.ko recognizes Prolific pl2303 properly. In fact, I can see some new device files in /dev/ while there's no such kind of files when only Alcor one is installed.


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## SirDice (May 18, 2015)

Shinyatti said:


> Hello. Recently I bought an USB-Serial converter card that has “Alcor Micro AU9720” chip shown below(Don’t ask me why I need Serial cables nowadays).


Nothing wrong with a serial connection. I use one quite frequently, a lot of older networking gear only has a serial console. 

Your best bet is to get one based on the mentioned PL2303 chipset or one with FTDI, I know these work without issues. That last one should be supported by uftdi(4). There's also ubsa(4), uark(4), umcs(4) and umct(4) but I've never used one of those.


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## wblock@ (May 18, 2015)

Either this is a regression or a new revision of that adapter which might use a different variation of the chipset.  Best to enter a PR, or ask on the freebsd-usb mailing list.


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## SirDice (May 19, 2015)

Yeah, it could be some variant. These chipsets seem to change a lot, without changing their type. I have two PL2303 based serial adapters, one works on Windows 7 and 8, the other doesn't. Same manufacturer, same type/model.


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## Shinyatti (Jul 21, 2016)

Thank you for advice, SirDice and wblock@ from 2016 

I solved this by buying genuine PL 2303 card.


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