[alsa-devel] usb 1-2: 1:1: cannot set freq 44100 to ep 0x81 and potential fix

[Joakim Tjernlund]

I have two USB headsets (Logitech Inc Logitech Stereo H650e and
Jabra Jabra UC VOICE 550a) who both causes lots of:

    usb 1-2: 1:1: cannot set freq 44100 to ep 0x81

errors when using them for pidgin audio chats. The actual freq
varies though.

I found that adding a small delay here:
 diff -u sound/usb/clock.c.org  sound/usb/clock.c 
--- sound/usb/clock.c.org	2017-08-18 14:38:05.597977669 +0200
+++ sound/usb/clock.c	2017-08-18 14:20:14.653661513 +0200
@@ -304,6 +304,7 @@
 			iface, fmt->altsetting, rate, ep);
 		return err;
 	}
+        msleep(1);
 
 	/* Don't check the sample rate for devices which we know don't
 	 * support reading */

it seems one cannot do these settings too fast
Ant better idea for a fix? kernel 4.9.44

 Jocke

PS.
   When starting a chat with pidgin-sipe, I see the same sample rate
freq setting twice, not sure where that comes from.