Unable to create IIO context ip:

[pooriayaghini]

Hi,

I am trying to work with PyAdi, but seems like it's not able to get the context through the IP.
I have tried this on both Mac and Windows. I am wondering if you can help me understand what's going wrong. Here is the error I am getting:

PS C:\Windows\System32> .\iio_info.exe --uri 'ip:192.168.1.196'
Library version: 0.20 (git tag: 26c5be5)
Compiled with backends: xml ip usb serial
Entity: line 1: parser error : Unescaped '<' not allowed in attributes values
armv7l" ><context-attribute name="hdl_system_id" value="[fmcomms2] on [zed] git <
^
ERROR: Unable to parse XML file
Unable to create IIO context ip:192.168.1.196: Invalid argument

Thanks,
Pooria

[tfcollins]

Can you provide more detail on the setup?
What version of libiio is running on the board?
What SD card version are you using on the Zed+FMComms2/3 combination?

-Travis

[rgetz]

This should have been fixed with this commit:

71bdda5

What is the library version on the host and remote?

[pooriayaghini]

Here is the configuration:

On Windows 10, libiio Library version: 0.20 (git tag: 26c5be5)
On Zynq: Ubuntu 14.04 (GNU/Linux 4.14.0-g8a57ede armv7l) + 04 February 2020 release (2019_R1 RC)

analog@analog:~/work/libiio/build$ /usr/bin/iio_info -u ip:127.0.0.1
Library version: 0.20 (git tag: 26c5be5)

Thanks,
Pooria

[rgetz]

that doesn't make sense.

If you go to the Zynq, and run iio_info there, what version is there?

The default version of libiio on 2019_R1 will not read the /etc/libiio.ini file, which is where the hdl_system_id is.

[pooriayaghini]

The bio_info seem to work fine on "local:" . But when tried to from remote terminal, or even on the Zynq with ip:127.0.0.1, it throws an error.

Here is the iio_info output when run on Zynq:

Library version: 0.20 (git tag: 26c5be5)
Compiled with backends: local xml ip
IIO context created with local backend.
Backend version: 0.20 (git tag: 26c5be5)
Backend description string: Linux analog 4.14.0-g8a57ede #652 SMP PREEMPT Mon Feb 3 16:34:57 GMT 2020 armv7l
IIO context has 3 attributes:
hdl_system_id: [fmcomms2] on [zed] git <2e4ac278eb09c13471e381459b0da790ebad8373> clean [2019-12-04 23:47:35] UTC
local,kernel: 4.14.0-g8a57ede
uri: local:
IIO context has 6 devices:
iio:device0: ad7291
9 channels found:
voltage6: (input)
2 channel-specific attributes found:
attr 0: raw value: 0
attr 1: scale value: 0.610351562

[rgetz]

yes - that is what described in the issue #519 - which PR #526 fixed (for me).

what I get is:

iio_info | less
Library version: 0.20 (git tag: 3cc5382)
Compiled with backends: local xml ip serial
IIO context created with local backend.
Backend version: 0.20 (git tag: 3cc5382)
Backend description string: Linux analog 4.19.0-g8221591d5e32 #1 SMP PREEMPT Wed May 20 14:32:17 EDT 2020 armv7l
IIO context has 9 attributes:
        hdl_system_id: [fmcomms2] on [zed] git <2e4ac278eb09c13471e381459b0da790ebad8373> clean [2019-12-04 23:47:35] UTC
        hw_model: AD-FMCOMMS2-EBZ on Xilinx Zynq ZED (armv7l)
        hw_carrier: Xilinx Zynq ZED
        hw_mezzanine: AD-FMCOMMS2-EBZ
        hw_name: AD9361 RF Hardware Development Kit
        hw_vendor: Analog Devices
        hw_serial: 00100
        local,kernel: 4.19.0-g8221591d5e32
        uri: local:

iio_info -u ip:127.0.0.1 | less
Library version: 0.20 (git tag: 3cc5382)
Compiled with backends: local xml ip serial
IIO context created with network backend.
Backend version: 0.20 (git tag: 26c5be5)
Backend description string: 127.0.0.1 Linux analog 4.19.0-g8221591d5e32 #1 SMP PREEMPT Wed May 20 14:32:17 EDT 2020 armv7l
IIO context has 10 attributes:
        hdl_system_id: [fmcomms2] on [zed] git <2e4ac278eb09c13471e381459b0da790ebad8373> clean [2019-12-04 23:47:35] UTC
        hw_model: AD-FMCOMMS2-EBZ on Xilinx Zynq ZED (armv7l)
        hw_carrier: Xilinx Zynq ZED
        hw_mezzanine: AD-FMCOMMS2-EBZ
        hw_name: AD9361 RF Hardware Development Kit
        hw_vendor: Analog Devices
        hw_serial: 00100
        local,kernel: 4.19.0-g8221591d5e32
        uri: ip:127.0.0.1
        ip,ip-addr: 127.0.0.1

and from a remote:

./tests/iio_info -u ip:192.168.1.120 | less
Compiled with backends: local xml ip usb serial
IIO context created with network backend.
Backend version: 0.20 (git tag: 26c5be5)
Backend description string: 192.168.1.120 Linux analog 4.19.0-g8221591d5e32 #1 SMP PREEMPT Wed May 20 14:32:17 EDT 2020 armv7l
IIO context has 10 attributes:
        hdl_system_id: [fmcomms2] on [zed] git <2e4ac278eb09c13471e381459b0da790ebad8373> clean [2019-12-04 23:47:35] UTC
        hw_model: AD-FMCOMMS2-EBZ on Xilinx Zynq ZED (armv7l)
        hw_carrier: Xilinx Zynq ZED
        hw_mezzanine: AD-FMCOMMS2-EBZ
        hw_name: AD9361 RF Hardware Development Kit
        hw_vendor: Analog Devices
        hw_serial: 00100
        local,kernel: 4.19.0-g8221591d5e32
        uri: ip:192.168.1.120
        ip,ip-addr: 192.168.1.120
IIO context has 8 devices:

Can you confirm in context.c there is a call to encode_xml_ndup?

and that the version of libxml2 on your system is 2.91 or higher?

On my Zynq image:

/usr/lib/arm-linux-gnueabihf/libxml2.so.2.9.1

on my host:

/usr/lib/x86_64-linux-gnu/libxml2.so.2.9.4

[rgetz]

also to confirm - when you updated the zynq board - you rebooted things?

[pooriayaghini]

Thanks Robin, Rebooting fixed the issue.

[rgetz]

OK - for future reference - just installing will not stop/restart the existing/running iiod, which will have the old libiio mmapped into memory. you need to restart iiod.

make install is not the same as /etc/init.d/iiod restart