unruh wrote:
On 2010-03-11, Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote:
Modern Linux kernels don't support PPS in the sense of RFC-whateveritis.
There is support for an ioctl that says wake me up when a modem signal
changes.
gpsd uses that to provide PPS support. I don't
David Woolley wrote:
So? The interrupt still takes the same time to be activated. On a GHZ
system, there is enough time in 1usec to run 1000 commands, and it is
hard to imagine that many being used to return the ioctl. I have worried
That's 1000 machine cycles, not 1000 instructions. On modern
David Woolley wrote:
That's 1000 machine cycles, not 1000 instructions. On modern systems,
I'm not sure that 1000 cycles isn't a typical time for a system call on
modern, high level language progammed, bloatware. (I seem to remember
hand coding an ISR in assembler to a budget of 100
On 2010-03-12, David Woolley da...@ex.djwhome.demon.invalid wrote:
unruh wrote:
On 2010-03-11, Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote:
Modern Linux kernels don't support PPS in the sense of RFC-whateveritis.
There is support for an ioctl that says wake me up when a modem
unruh wrote:
On 2010-03-12, David Woolley da...@ex.djwhome.demon.invalid wrote:
unruh wrote:
On 2010-03-11, Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote:
Modern Linux kernels don't support PPS in the sense of RFC-whateveritis.
There is support for an ioctl that says wake me
unruh wrote:
On 2010-03-12, Terje Mathisenterje.mathisen at tmsw.no wrote:
OTOH, I have personally never seen this on any of my S1 servers which
all use the serial port.
Not sure how you would see that. If the interrupt were delayed by one
ms ntp would not know. It would see something only
On 2010-03-12, Uwe Klein uwe_klein_habertw...@t-online.de wrote:
unruh wrote:
On 2010-03-12, David Woolley da...@ex.djwhome.demon.invalid wrote:
unruh wrote:
On 2010-03-11, Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net
wrote:
Modern Linux kernels don't support PPS in the sense of
unruh wrote:
I cerainly would not rely on the data in/out for the interrupt as it
might well have clock aliasing. But is there not a specific pin on the
serial port which is an immediate interrupt pin like the interrupt pin
on the parallel port?
The hardware supports interrupt on DCD, DTR,
