pps_ioctl panic

[O'Connor, Daniel]

> On 30 Apr 2015, at 04:26, Hans Petter Selasky <hps at selasky.org> wrote:
> 
> On 04/29/15 06:58, O'Connor, Daniel wrote:
>> 
>>> On 28 Apr 2015, at 17:05, Hans Petter Selasky <hps at selasky.org> wrote:
>>> 
>>> On 04/28/15 09:08, O'Connor, Daniel wrote:
>>>> Hi all,
>>>> I'm trying to get gpsd + PPS working on a Beaglebone Black but when I start gpsd I get the panic at the bottom of the email.
>>>> 
>>>> I've run ntpd to the same device with PPS without problems.
>>>> 
>>>> I haven't had a more detailed look yet though.
>>> 
>>> Hi,
>>> 
>>> Try to set "pps.mtx = &ttymx" before "pps_init()".
>> 
>> I tried adding both..
>>         sc->pps.mtx = &ttymx;
>> and
>>         sc->pps.mtx = &ttymtx;
>> 
>> but neither mutex exist. I had a look in the TTY code (sys/kern/tty.c) and I couldn't see a likely candidate.
>> 
> Have a look in "sys/dev/usb/serial/usb_serial.c"

OK I see.

I had a better look and it seems odd. am335x_dmtimer.c doesn't have any locks that I can see - certainly not TTY ones.

I don't understand how the thread still has a TTY lock when the dmtpps device isn't a TTY :(

--
Daniel O'Connor
"The nice thing about standards is that there
are so many of them to choose from."
 -- Andrew Tanenbaum
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