Date: Sat, 18 Dec 2004 18:52:01 -0800 From: steve@Watt.COM (Steve Watt) To: freebsd-usb@freebsd.org Subject: panic w/ USB<->serial adapter and modem Message-ID: <200412190252.iBJ2q1eW002380@wattres.watt.com>
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I've got a 5.3-STABLE (updated 19 Nov around 2000PST) machine that has serious difficulty when I attempt to use the modems that are attached via the Prolofic Technology PL2303 serial adapters. It seems that the kernel panics when carrier drops, during the general TTY cleanup. Here's a hand-transcribed trace from the one I saw this afternoon. Note that I didn't bother writing down all of the addresses in all of the functions, those are listed as "...". I include the line number and source line from GDB (ex-post-facto) as well. Some of the latter is guessing, since it wasn't a debug kernel. - - - 8< - - - hand-entered off my scribbled notes - - - panic: uhci_abort_xfer: not in process context KDB: enter: panic [ thread 100027 ] kdb> trace kdb_enter(...) panic(...) at panic + 0xce uhci_abort_xfer(c19f8b00,6,caca1b80,c05f328f,c19f8b00) at uhci_abort_xfer + 0x8b 1954 if (xfer->device->bus->intr_context || !curproc) 1955 panic("uhci_abort_xfer: not in process context"); uhci_device_bulk_abort(...) at uhci_device_bulk_abort + 0x19 1919 uhci_abort_xfer(xfer, USBD_CANCELLED); usbd_ar_pipe(...) at usbd_ar_pipe + 0x22 747 /* Make the HC abort it (and invoke the callback). */ 748 pipe->methods->abort(xfer); usbd_abort_pipe(..) at usbd_abort_pipe + 0x11 547 s = splusb(); 548 err = usbd_ar_pipe(pipe); ucomstopread(c156ad00,1,c1559e00,3,caca1bc8) at ucomstopread+0x28 1156 err = usbd_abort_pipe(sc->sc_bulkin_pipe); ucomstop(...) at ucomstop+0x44 933 DPRINTF(("ucomstop: read\n")); 934 ucomstopread(sc); ttyflush(c1559e00,3,0,1,5) at ttyflush+0x43 1420 (*tp->t_stop)(tp, rw); ttymodem(...) at ttymodem+0x194 1614 ttyflush(tp, FREAD | FWRITE); ucom_status_change(c156ad00,caca1c4c,...) at ucom_status_change+0x73 759 ttyld_modem(tp, onoff); uplcom_intr(c19f9900,c156ad00,0,0,1) at uplcom_intr+0x69 805 ucom_status_change(&sc->sc_ucom); usb_transfer_complete(c19f9900,0,caca1cbc,a,c26cc00) at usb_transfer_complete+0x135 845 pipe->methods->done(xfer); uhci_idone(c19f996c,0) at uhci_idone+0x11d 1497 end: 1498 usb_transfer_complete(xfer); uhci_check_intr(c1595000,...) at uhci_check_intr+0x93 1372 usb_uncallout(ii->xfer->timeout_handle, uhci_timeout, ii); 1373 uhci_idone(ii); uhci_softintr(c1595000,...) at uhci_softintr+0x2b 1303 LIST_FOREACH_SAFE(ii, &sc->sc_intrhead, list, nextii) 1304 uhci_check_intr(sc, ii); usb_schedsoftintr(c1595000,7058c,c15a0040,4,c146b380) at usb_schedsoftintr+0x12 859 bus->methods->soft_intr(bus); uhci_intr1(c1595000,...) at uhci_intr1+0x18c 1274 usb_schedsoftintr(&sc->sc_bus); uhci_intr(c1595000,0,0,0,0) at uhci_intr+0x2e 1189 return (uhci_intr1(sc)); ithread_loop(...)... fork_exit(...)... fork_trampoline(...)... - - - >8 - - - hand-entered off my scribbled notes - - - So it's pretty clear, reading that over, that uhci_abort_xfer *IS* being called from interrupt context, namely when carrier drops. There's some kind of think-o happening in there, but I'm not sure quite what to do about it. It also looks like there's some risk of ugly recursion, because usb_transfer_complete is called from uhci_abort_xfer, but I really haven't analyzed the code path well enough to be certain that it's OK. My kernel config is pretty much GENERIC, and usbdevs -v looks like: Controller /dev/usb0: addr 1: full speed, self powered, config 1, UHCI root hub(0x0000), VIA(0x0000), rev 1.00 port 1 powered port 2 powered Controller /dev/usb1: addr 1: full speed, self powered, config 1, UHCI root hub(0x0000), VIA(0x0000), rev 1.00 port 1 addr 2: full speed, self powered, config 1, Generic USB Hub(0x9254), ALCOR(0x058f), rev 3.12 port 1 addr 3: full speed, power 500 mA, config 1, PL2303 Serial adapter (ATEN/IOGEAR UC232A)(0x2303), Prolific Technology(0x067b), rev 2.02 port 2 addr 4: full speed, power 500 mA, config 1, PL2303 Serial adapter (ATEN/IOGEAR UC232A)(0x2303), Prolific Technology(0x067b), rev 2.02 port 3 addr 5: full speed, power 500 mA, config 1, PL2303 Serial adapter (ATEN/IOGEAR UC232A)(0x2303), Prolific Technology(0x067b), rev 2.02 port 4 powered port 2 powered Controller /dev/usb2: addr 1: full speed, self powered, config 1, UHCI root hub(0x0000), VIA(0x0000), rev 1.00 port 1 powered port 2 powered -- Steve Watt KD6GGD PP-ASEL-IA ICBM: 121W 56' 57.8" / 37N 20' 14.9" Internet: steve @ Watt.COM Whois: SW32 Free time? There's no such thing. It just comes in varying prices...
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