In message: <[EMAIL PROTECTED]> [EMAIL PROTECTED] (Bill Paul) writes: : When I got it home, I found that almost everything is supported in : FreeBSD 5.x, except for one thing: the serial port. The chip is a : MCT USB-232 device, which is supported in NetBSD, but not FreeBSD.
But Scott Long already committed his umct driver a few days ago... :-)
Warner
Yes, so I have been told. :P
And guess what. It has a bug. :)
Well ok, to be fair, it doesn't really have a bug: it lacks a workaround for a buggy chip. The driver determines the bulk output buffer size by checking the data returned by the chip in its bulk out endpoint descriptor. This is right in most cases, but not for the USB_PRODUCT_MCT_SITECOM_USB232 device (which, unfortunately, is what they put in the port replicator I bought). The value it returns for wMaxPacketSize is 32, but in reality, you must use 16. If you don't, the chip drops data under certain circumstances. A good example: attach a modem to the serial adapter and set up a PPP link over it, then try to ssh to a remote host somewhere. Ssh will get about halfway through the connection attempt and then hang. I observed a similar problem with my IRC client.
It turns out the NetBSD driver that I hacked up worked because it has a workaround for this chip bug. I applied a similar workaround to Scott's driver and now PPP works again. Here's a patch:
--- umct.c.orig Thu Jul 3 18:50:39 2003
+++ umct.c Mon Jul 7 00:52:55 2003
@@ -241,7 +241,10 @@
if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT) {
ucom->sc_bulkout_no = ed->bEndpointAddress;
- ucom->sc_obufsize = UGETW(ed->wMaxPacketSize);
+ if (uaa->product == USB_PRODUCT_MCT_SITECOM_USB232)
+ ucom->sc_obufsize = 16; /* device is broken */
+ else
+ ucom->sc_obufsize = UGETW(ed->wMaxPacketSize);
continue;
}
This is almost literally what NetBSD does. Barring any objections, I'd like to check this in. (CC'ing Scott on this e-mail.)
Bill,
Excellent, feel free to commit this. I remember seeing this workaround, but since I didn't have the device that it applied to I must have dropped the code by accident.
Scott
_______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
