Accessing usb serial adapter HL-340 panics system

Jan Lentfer Jan.Lentfer at
Sat Jan 9 10:32:57 PST 2010

This patch fixes the panic according to my tests:

diff --git a/sys/dev/usbmisc/uchcom/uchcom.c 
index 353552e..d925d9c 100644
--- a/sys/dev/usbmisc/uchcom/uchcom.c
+++ b/sys/dev/usbmisc/uchcom/uchcom.c
@@ -276,6 +276,7 @@ uchcom_attach(device_t self)
        sc->sc_intr_size = endpoints.ep_intr_size;

        /* setup ucom layer */
+       ucom->sc_parent = sc;
        ucom->sc_portno = UCOM_UNK_PORTNO;
        ucom->sc_bulkin_no = endpoints.ep_bulkin;
        ucom->sc_bulkout_no = endpoints.ep_bulkout;
Now I can use tip and cu and minicom on /dev/ucom0 without panicing the 
system. But still it won't really work. I get such messages in dmesg:
ucom0: ucomreadcb: IOERROR
ucom0: ucomreadcb: IOERROR
ucom0: ucomreadcb: IOERROR
ucom0: ucomreadcb: CANCELLED
ucom0: cannot reset: IOERROR


putc to a clist with no reserved cblocks

I found an error description for FBSD and another driver that seems 
match otherwise:

But I am not really getting much out of that. Maybe someone could read 
through that and evaluate if this helps in my case?

Thanks a lot in advance


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