linux/drivers/usb/gadget
Peter Chen 08ccc8bb7d usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth
commit 913e4a90b6 upstream.

According to USB Audio Device 2.0 Spec, Ch4.10.1.1:
wMaxPacketSize is defined as follows:
Maximum packet size this endpoint is capable of sending or receiving
when this configuration is selected.
This is determined by the audio bandwidth constraints of the endpoint.

In current code, the wMaxPacketSize is defined as the maximum packet size
for ISO endpoint, and it will let the host reserve much more space than
it really needs, so that we can't let more endpoints work together at
one frame.

We find this issue when we try to let 4 f_uac2 gadgets work together [1]
at FS connection.

[1]http://www.spinics.net/lists/linux-usb/msg123478.html

Acked-by: Daniel Mack <zonque@gmail.com>
Cc: andrzej.p@samsung.com
Cc: Daniel Mack <zonque@gmail.com>
Cc: tiwai@suse.de
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2015-09-21 10:05:38 -07:00
..
function usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth 2015-09-21 10:05:38 -07:00
legacy usb: gadget: g_ffs: Fix counting of missing_functions 2015-05-26 10:15:08 -05:00
udc usb: gadget: m66592-udc: forever loop in set_feature() 2015-09-21 10:05:37 -07:00
composite.c usb: gadget: composite: Fix NULL pointer dereference 2015-08-03 09:29:05 -07:00
config.c usb: gadget: always update HS/SS descriptors and create a copy of them 2012-10-31 15:09:44 +02:00
configfs.c usb: gadget: configfs: Fix interfaces array NULL-termination 2015-04-27 14:44:04 -05:00
configfs.h usb: gadget: OS descriptors: provide interface directory names 2014-06-19 10:06:48 -05:00
epautoconf.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00
functions.c usb: gadget: add a forward pointer from usb_function to its "instance" 2013-01-21 20:52:46 +02:00
Kconfig usb: gadget: f_printer: fix dependencies 2015-03-24 11:35:21 -05:00
Makefile usb: gadget: use $(srctree) instead of $(PWD) for includes 2014-08-29 15:53:46 -05:00
u_f.c usb: gadget: only GPL drivers in the gadget and phy framework 2014-04-21 14:07:12 -05:00
u_f.h usb: gadget: FunctionFS: share VLA macros with all usb gadget files 2014-05-14 09:37:27 -05:00
u_os_desc.h usb: gadget: u_os_desc: helper functions for accessing ext prop buffer 2014-07-10 08:36:51 -05:00
usbstring.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00