Support multiple Airspy devices
Please, consider supporting multiple Airspy devices in gr-osmosdr. Currently, this is not possible and only one of my connected Airspy R2 devices is available in GNU Radio companion and Gqrx.
There was a patch adding this support (by being able to specify the device serial number as a value for the "airspy" argument in Airspy Source) already posted in 2016: https://lists.osmocom.org/pipermail/osmocom-sdr/2016-April/001446.html
The patch still seems to work fine on latest gr-osmosdr and adds exactly the functionality needed to make multiple Airspy devices available. Please, consider adding this patch to upstream gr-osmosdr or implementing a different approach to support multiple Airspy devices in gr-osmosdr. Thanks!
I have found out that even though the patch works fine, it has one behavior change that could be considered as an regression. :( When this patch is applied, the Airspy Source does not find any devices when an "airspy" argument is specified without any value (just "airspy"). It works fine when specifying it as "airspy=0" (which is what Gqrx does by default). I have found no other issues besides this and both my Airspy R2 SDRs work fine now after specifying them by their serial numbers.
This patch seems useful, I merged it to Fedora downstream, Fedora bugzilla:
I also fixed initialization in the patch, so it now works correctly even if no device arguments are given or s/n is 0. In such case the first found airspy device is used. Modified patch is attached.
This is just proposal, in case you come up with different upstream solution I am ready to sync it with the Fedora downstream.