Re: Mode/Status not updated in shared mem mode

[Gary E. Miller]

Yo Hans!

On Mon, 6 Jan 2025 10:15:47 +0100
Hans Kurscheidt <lve0200@gmail.com> wrote:

> Hi, its not about Telepathy... :(
> 
> its about a middle-ware, which does not flag the validity of its
> data!

Of course it does.  But it can not flag the validity of data it never
gets.

> I wonder, what the difficulty is.

GIGO, Garbage In, Garbage Out.  It there is no garbage in from the
receiver, then there is nothing to flag good or bad.


> In my simple mind, it could
> be solved by a simple semaphore like thing,

Like the fix status flag?  Or the other validity flags gpsd uses?

> where read_gps would set
> it to 0 and a new write from the GPS device would set it to 1.

But what if no read?

> So if
> the GPS device disconnects, the semaphore remains 0 and the APP can
> recognize, there there's only obsolete data.

Info on disconencts is in the JSON already.

But it is unclear exactly what is happening to you.  Is your receiver
disconnecting?  Timeing out?  Or.

Please explain the command line you use to start gpsd, and what you
have connected to it.

> I ran into this problem, because Debian at some point in time (aft.
> 20 min) decided to put the USB controller into Power Safe state,
> despite the fact that GPS was connected and working.

Sounds like a debian problem.  You can use tools like powettop to
force USB to stay on.  Then you need to turn off sleep, hibernation, etc.

Nothing gpsd can do if the under lying host shuts down.

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  Tel:+1 541 382 8588

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