libusb1: auto-select interface 1 for Liebert PSI5 / PowerSure PST (10af:0002)

NEWS.adoc

@@ -62,6 +62,8 @@ https://github.com/networkupstools/nut/milestone/12
      other too. [issue #3136]
    * Improved high-verbosity debug tracing of NUT `libhid` and `usbhid-ups`
      to help make sense of data processing issues (HID paths, strings). [#3201]
+   * Liebert devices with USB ID `10af:0002` should default to HID Interface 1
+     (not 0) to serve the HID Power Device Class telemetry. [#3345]
    * Further removal of unbounded `strcpy()` and `sprintf()` usage. [#3253]
    * For state tree methods, introduced `difftime_st_tree_timespec()` to
      abstract platform-dependent definitions of `st_tree_timespec_t`. [PR #3156]

drivers/libusb0.c

@@ -468,6 +468,17 @@ static int nut_libusb_open(usb_dev_handle **udevp,
 					usb_subdriver.hid_desc_index = 1;
 			}
 
+			/* Liebert PSI5 / PowerSure PST (10af:0002): the HID Power Device
+			 * Class descriptor is on interface 1.  Interface 0 exposes only a
+			 * 27-byte vendor-specific report that contains no usable UPS data,
+			 * which caused NUT to incorrectly report the UPS as on battery
+			 * (OB) even when AC power was present.
+			 * See GitHub issues #1252 and #3340. */
+			if ((curDevice->VendorID == 0x10af) && (curDevice->ProductID == 0x0002)) {
+				if (!getval("usb_hid_rep_index"))
+					usb_subdriver.hid_rep_index = 1;
+			}
+
 			upsdebugx(2, "Trying to match device");
 			for (m = matcher; m; m=m->next) {
 				ret = matches(m, curDevice);

drivers/libusb1.c

@@ -476,6 +476,17 @@ static int nut_libusb_open(libusb_device_handle **udevp,
 				usb_subdriver.hid_desc_index = 1;
 		}
 
+		/* Liebert PSI5 / PowerSure PST (10af:0002): the HID Power Device
+		 * Class descriptor is on interface 1.  Interface 0 exposes only a
+		 * 27-byte vendor-specific report that contains no usable UPS data,
+		 * which caused NUT to incorrectly report the UPS as on battery
+		 * (OB) even when AC power was present.
+		 * See GitHub issues #1252 and #3340. */
+		if ((curDevice->VendorID == 0x10af) && (curDevice->ProductID == 0x0002)) {
+			if (!getval("usb_hid_rep_index"))
+				usb_subdriver.hid_rep_index = 1;
+		}
+
 		upsdebugx(2, "Trying to match device");
 		for (m = matcher; m; m=m->next) {
 			ret = matches(m, curDevice);