I think this belongs at linux-usb@xxxxxxxxxxxxxxx, forwarding (converting the attachment inline). Perhaps a better option would be to poke around drivers/usb/core/config.c, but I do not remember details anymore, so I may be wrong. I'll try to look at it tomorrow. -- Pete Begin forwarded message: Date: Sat, 10 Dec 2011 19:45:39 +0000 From: "Richard W.M. Jones" <rjones@xxxxxxxxxx> To: alsa-devel@xxxxxxxxxxxxxxxx Cc: Tom Walder <tom.walder@xxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx Subject: [PATCH] Jabra SPEAK 410 USB - no audio playback The attached patch fixes USB audio support for the Jabra SPEAK 410 USB. The problem, as I understand it, is that the device contains a Class-Specific Endpoint (CS_ENDPOINT) descriptor before the Endpoint (ENDPOINT) descriptor. The USB code all assumes that CS_ENDPOINT can only appear after ENDPOINT. Therefore the USB code divides up the interface descriptor into "stuff before ENDPOINT" (in interface->extra) and "stuff after ENDPOINT" (in interface->endpoint[0]->extra). For this device, this division does not work. You can see lsusb for my device here: http://mailman.alsa-project.org/pipermail/alsa-devel/2011-December/047036.html Notice the "** UNRECOGNIZED: 07 25 01 81 02 00 00" line which is the CS_ENDPOINT descriptor. The solution (which is a hack ...) is to also search interface->extra looking for the missing descriptor. For me, this fully enables the functions of this device. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming blog: http://rwmj.wordpress.com Fedora now supports 80 OCaml packages (the OPEN alternative to F#) http://cocan.org/getting_started_with_ocaml_on_red_hat_and_fedora diff -uNrp kernel-3.1.fc16.orig/sound/usb/stream.c kernel-3.1.fc16.new/sound/usb/stream.c --- kernel-3.1.fc16.orig/sound/usb/stream.c 2011-12-10 18:03:29.658729051 +0000 +++ kernel-3.1.fc16.new/sound/usb/stream.c 2011-12-10 18:08:41.468694907 +0000 @@ -164,6 +164,12 @@ static int parse_uac_endpoint_attributes csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT); + /* Jabra SPEAK 410 USB has CS_ENDPOINT before ordinary ENDPOINT, + * which confuses the USB descriptor parsing code. Try looking + * for CS_ENDPOINT in the interface->extra - RWMJ. */ + if (!csep) + csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT); + /* Creamware Noah has this descriptor after the 2nd endpoint */ if (!csep && altsd->bNumEndpoints >= 2) csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT); -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
