[LinuxPPS] do we need hardpps <- yes!!

[Udo van den Heuvel]

On 2010-02-06 15:08, Remco dB wrote:
>> I was thinking of using the falling edge trick for serial GPS as well.
>> But this doesn't look so feasible now with this GPS.
> 
> For more precision concerning the second epochs, a Motorola
> Oncore GPS-receiver could be used. 
> At this time of writing a Chinese supplier sells UT+'s for U$ 5.00 (!)
> excl posting and shipping on Ebay. 

Interesting!
I have my Motorola's here.
I still haven't come to implement them. (would need to put the antenna
on the edge of the roof)

Also: would running 2 GPS receivers on one irq be bad?
Does LinuxPPS deal with that at all?

Hmm:
# cat /proc/interrupts
           CPU0
  0:         49   IO-APIC-edge      timer
  1:       1892   IO-APIC-edge      i8042
  3:   91401282   IO-APIC-edge      serial
  7:          0   IO-APIC-edge      parport0
  9:          0   IO-APIC-fasteoi   acpi
 14:          0   IO-APIC-edge      ide0
 15:   14706315   IO-APIC-edge      ide1
 17:      60933   IO-APIC-fasteoi   HiSax, HDA Intel
 18: 1521039453   IO-APIC-fasteoi   eth1
 19:  977446806   IO-APIC-fasteoi   eth0
 20:          0   IO-APIC-fasteoi   uhci_hcd:usb2
 21:          0   IO-APIC-fasteoi   uhci_hcd:usb4
 22:          0   IO-APIC-fasteoi   uhci_hcd:usb3
 23:          0   IO-APIC-fasteoi   ehci_hcd:usb1
NMI:          0   Non-maskable interrupts
LOC:  953308699   Local timer interrupts
SPU:          0   Spurious interrupts
ERR:          0
MIS:          0

Strangely I do not see my gps (ttyS0, irq4?) but I do see interrupt 3 (ups).
Why?