libusb in context

[rgetz]

to help debug some libusb issues we were having, I added this code:

diff --git a/usb.c b/usb.c
index 2a48744..e5ef23e 100644
--- a/usb.c
+++ b/usb.c
@@ -699,6 +699,7 @@ static int usb_populate_context_attrs(struct iio_context *ctx,
                const char *attr;
                uint8_t idx;
        } attrs[3];
+       struct libusb_version const *ver;

        libusb_get_device_descriptor(dev, &dev_desc);

@@ -740,6 +741,14 @@ static int usb_populate_context_attrs(struct iio_context *ctx,
                }
        }

+       ver = libusb_get_version();
+       iio_snprintf(buffer, sizeof(buffer), "%i.%i.%i.%i%s %s",
+                       ver->major, ver->minor, ver->micro,
+                       ver->nano, ver->rc, ver->describe);
+       ret = iio_context_add_attr(ctx, "local,libusb", buffer);
+       if (ret < 0)
+               return ret;
+
        return 0;
 }

which seems to be pretty straightforward, I just wanted to understand the preference - "local,libusb", or "usb,libusb", or something else? I expect something else will need to go into the iiod/usbd.c:usb_open_pipe() to add the remote version as well.

the above prints out:

analog@imhotep:~/github/libiio$ iio_attr -a -C
Using auto-detected IIO context at URI "usb:3.2.5"
IIO context with 8 attributes:
local,kernel: 4.6.0-08783-g1cc7526
usb,idVendor: 0456
usb,idProduct: b673
usb,release: 2.0
usb,vendor: Analog Devices Inc.
usb,product: PlutoSDR (ADALM-PLUTO)
usb,serial: 104473222a8700071a002b001f4dd56fb8
local,libusb: 1.0.21.11156 http://libusb.info

[pcercuei]

The prefix should be the backend that corresponds to the attribute, so it should be "usb,libusb".

No need to modify iiod, the remote will never use libusb (it uses FunctionFS).

[rgetz]

So, did you want a pull request for this?

[pcercuei]

That would be great, yes.

[rgetz]

This is tracked in #207 now