Re: [gpsd-dev] GPSd re-scan on connect

[Gary E. Miller]

Yo Larry!

On Wed, 10 Apr 2019 09:08:33 -0400
Larry Boyd <address@hidden> wrote:

> First of all, my apologies for emailing you directly. I was wondering
> why you weren't responding to some of my messages, and it looks like
> the mailing list is dropping them.

When in doubt, send to both gpsd-dev and directly.  The mailing list
does not like large attachaments.

OTOH, I do have several of your messages in my inbox.  Right now I
am fighting the WKRO bug thing.  Until the regressions work again
I'm not applying any new patches.  I'll send more info on that to the
gpsd-dev list later.

> There were two threads we were discussing;

When in doubt, best to use one thread per thread.  Not everyone
is interested in every discussion.

> - The first was relating to building and using the libgps client
> library on Android, which would be followed up with a gnss HAL and
> eventually gpsd itself.

To be clear, a native build ON an android system, right?

> - The second thread involved having gpsd attempt to re-add devices
> from the commandline upon client connection if the device list
> becomes empty.

Which still seems odd to me.  What devices do you have the come and go?
That a udev, or similar, rul can not handle?

> I have attached two patches to this email, note that neither is ready
> to be added just yet (in particular, since I have not had the
> opportunity to properly test them yet), I was hoping for you to
> comment on them before I complete them for submission (which I will
> do in the form of signed off git patches).

I'll look at them, but not until other stuff higher in my queue is
dealt with.  Specifically the regressions, but also some u-blox
stuff.

> readd_devices.patch will check if the device list is empty upon client
> connection and re-add those specified on the command line if there
> are any. I am confident that this one will work, since it precisely
> duplicates what happens when gpsd receives SIGHUP.

Did you reuse the SIGHUP code?  Or cut/paste?  Or?

Can you post that patch somewhere that other people can see it for comment?

> Note: this will be applicable to devices that are connected to the
> system *after* GPSd starts (including devices that may also have been
> removed after start), where either the system does not support udev
> (i.e. Android), or the device is connected to a bus that is not
> supported by udev (i.e. UART).

Android support hot plugging.  How do they do it?

> gpsd_aosp.patch makes it possible to build libgps.so as part of AOSP.
> Since scons is not a component of the AOSP build system, it was
> necessary to apply configurations manually.

You will regret not using scons.

> The majority of this
> patch is the Android.bp (the equivalent of a makefile to the AOSP
> build system) and avoiding use of the gpsd_config.h under Android,

Another decision you will regret.  Much better to hand build a
gpsd_config.h rather than patch out every place that includes
gpsd_config.h.

We are trying to reduce the numer of #ifdef, and this does the opposite.

> the other change is a hack to redefine gps_maskdump(..) to an empty
> string.

Better yet, just make your own copy that dumps the hex, without trying
to convert to strings.

> Note that none of the logging features will work under
> Android without radical changes, so nothing is actually lost to
> Android with that hack. Note: I am aware that there are a number of
> configurations I've added that are not required for the client
> library. Cleaning that up is part of the additional work to be done
> after obtaining your input on how best to move forward.

Can you post that patch somewhere that other people can see it for comment?

> Future plans;
> At the moment, I am working on an Android gnss 1.1 HAL to make use of
> libgps. It would be nice if this HAL could be included as part of the
> gpsd project.

As long as the license is clean then we can add an android directory
so others can play with the code.  Is the BSD-2 clause going to work
with the HAL, and the rest?

> Following this, it will be getting gpsd building under the AOSP build
> system and running locally.

And that will be fun, the cross-compiling stuff is always messy.

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

            Veritas liberabit vos. -- Quid est veritas?
    "If you can’t measure it, you can’t improve it." - Lord Kelvin

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