[PATCH] usb: gadget: f_uac2: calculate wMaxPacketSize before endpoint match

From: Sekhar Nori
Date: Wed May 17 2017 - 04:15:33 EST


Calculate wMaxPacketSize before endpoint matching the
descriptor is found.

This allows audio gadget to be used with controllers
which have a shortage or unavailability of endpoints
that can handle max packet size of 1023 (FS) or 1024
(HS).

With this audio gadget can be used on TI's OMAP-L138 SoC
which has a MUSB HS controller with endpoints having max
packet size much less than 1023 or 1024. See mode_2_cfg in
drivers/usb/musb/musb_core.c

Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
---
drivers/usb/gadget/function/f_uac2.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index f6a0d3a1311b..5a7ba058d947 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -1065,6 +1065,12 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->as_in_intf = ret;
agdev->as_in_alt = 0;

+ /* Calculate wMaxPacketSize according to audio bandwidth */
+ set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
+ set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
+ set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
+ set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
+
agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
if (!agdev->out_ep) {
dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
@@ -1080,12 +1086,6 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
uac2->p_prm.uac2 = uac2;
uac2->c_prm.uac2 = uac2;

- /* Calculate wMaxPacketSize according to audio bandwidth */
- set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
- set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
- set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
- set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
-
hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;

--
2.9.0