Re: [gpsd-dev] Linux kernel bug in 3:12, low_latency on serial ports is broken

[Beat Bolli]

Hi Hal

I had reported this to linux-serial: 
http://marc.info/?t=139125913700001&r=1&w=2

I could not make sense of the replies, however.

serial.c does not mention "low-latency" at all. Is the 
port->low_latency flag set by
"session->ttyset.c_cc[VMIN] = 1;" in serial.c:494?

Regards,
Beat

On 2014-02-20 09:31, Hal Murray wrote:
> Just a heads-up in case you hit this, or want to avoid it.
>
> The symptom is BUG: scheduling while atomic
>   https://bugzilla.redhat.com/show_bug.cgi?id=1065087
>
> The discussion at
>   https://lkml.org/lkml/2014/2/18/77
> confirms that it's the low-latency path that is buggy.
>
> My setup works fine under low load, but hits the BUG when I do
> something like
> compile the ntp package.
>
> 3.11 works fine.  (for me)  There was major work in the serial area 
> for 3.12
>
> I'll send an update when/if it gets fixed.

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