Urgent: usbserial driver problems with GPS card, where to find help?

From: Kevin Lamonte (lamonte_at_gerg.tamu.edu)
Date: 10/25/04 

Date: Mon, 25 Oct 2004 09:37:27 -0500

I'm having several serious problems with the usbserial driver in
conjuction with a NovAtel GPS receiver card (OEM4-G2 model).

Questions:

1) Can anyone point me to the appropriate forum to ask the actual
usbserial developers?

2) Does the serial port speed affect the usbserial driver at all? Does
it really alter the rate that data can be read from the USB device?

3) Can the usbserial.c from 2.4.27 be retrofitted to 2.4.22-ac4 safely?
  I see that if I copy usb-serial.h and usbserial.c to
drivers/usb/serial, the 'make modules' command succeeds. Are there any
other changes between 2.4.22-ac4 and 2.4.27 that need to be included?

Problems:

1) We are losing *some* data sent from the card to the PC104. Last
night I powered up the GPS card and PC104 and left it on. At midnight
my reader program shutdown and was re-started (by design). The second
instance of the reader immediately started seeing data loss on
/dev/ttyUSB0. After the PC104 rebooted, however, it started working fine.

2) If we shutdown the GPS card while leaving the computer on, AND a
reader is on /dev/ttyUSB[0-2], the usbserial driver OOPSes. I've seen
this described and several patches for the behavior that seem to
culminate in the 2.4.27 driver.

3) If the reader does not get to /dev/ttyUSBx quickly enough, that
particular device fails until the GPS card is power cycled. For
example, if the reader waits two minutes before opening /dev/ttyUSB1, it
will immediately read about two kilobytes of data and then nothing more,
even though the card is configured to emit about 100 bytes every two
seconds. /dev/ttyUSB0 still works fine, however. I cannot determine if
this problem is in usbserial or the NovAtel card.

Setup:

Kernel version: 2.4.22-ac4
Custom compile with usb-ohci, usbserial loaded as modules

The PC is a PC104 with the ZFMicro ZFx86 chipset. The USB controller is
on the same silicon as the 100Mhz 486 CPU; it is recongized as a Compaq
OHCI chipset.

The NovAtel GPS card is custom mounted with a cable that provides USB
connectivity and input power.

The usbserial driver is loaded as a module so I can pass in the vendor
and product IDs. After loading the usbserial driver and providing power
to the NovAtel, three devices are successfully "connected" to
/dev/ttyUSB0, /dev/ttyUSB1, and /dev/ttyUSB2.

I can use minicom to communicate with the NovAtel card. My program can
read data from the card, and 'cat /dev/ttyUSB0' works. However, we get
problems after leaving it on for a few hours.

The ports are being run at 19200, 8N1, set via tcsetattr().

Relevant Pages

  • Re: Garmin Xs, memory cards, and MapSource licenses
    ... They can do that by creating separate map files for each receiver. ... I've used a Magellan GPS. ... You can create map files to the SD cards in the GPS, to the SD card in a burner with the GPS attached, or with some versions at least, the SD card in a burner, no GPS attached, and by entering the GPS receiver's hardware serial number from the keyboard when the map file is created. ... For the purchased at retail version, you do that by going online with a SD card either in a reader or a attached GPS and entering the software serial number that is on the back of the BlueNav CD-ROM case. ...
    (sci.geo.satellite-nav)
  • Re: Threads, modules, processes...
    ... I've recently switched from an X50v to an X51v to find that my CF card GPS ... could be heared by the speaker, but when TTN5 were brought to foreground, ... serial DLL thread you are interested in has a unique priority, ...
    (microsoft.public.pocketpc.developer)
  • Re: Garmin Street Pilot C-530
    ... We don't care about Blue Tooth. ... We don't care that it doesn't announce street names, so long as they display across the top of the screen as our Garmin Quest does. ... We DO care about being able to plan a trip on the computer and send it to the GPS. ... Even my Garmin 320 will do those things once I put a larger memory card in for a few bucks. ...
    (rec.outdoors.rv-travel)
  • Re: Garmin Street Pilot C-530
    ... We don't care about Blue Tooth. ... We DO care about being able to plan a trip on the computer and send it to the GPS. ... Even my Garmin 320 will do those things once I put a larger memory card in for a few bucks. ... I haven't used mine but a month or so ago I posted a link to a download that allowed a Garmin GPS to be loaded with data from Street Atlas and various overlays of gas stations, POIs, restaurants, etc. ...
    (rec.outdoors.rv-travel)
  • Re: rooftop antenna range
    ... gps to talk to me. ... but the baseline is too far from Santa Cruz and their antenna is ... I was more interested in this card for its RX sensitivity. ... Fresnel Zone is a knife edge diffraction ...
    (alt.internet.wireless)