svn commit: r271492 - head/sys/dev/usb/serial

[Hans Petter Selasky]

Author: hselasky
Date: Fri Sep 12 22:40:12 2014
New Revision: 271492
URL: http://svnweb.freebsd.org/changeset/base/271492

Log:
  Workaround for receiving Voice Calls using the E1750 dongle from
  Huawei. It might appear as if the firmware is allocating memory blocks
  according to the USB transfer size and if there is initially a lot of
  data, like at the answering machine prompt, it simply dies without any
  apparent reason. The simple workaround for this is to force a zero
  length packet at hardware level after every 512 bytes of data. This
  will force the other side to use smaller memory blocks aswell.
  
  MFC after:	1 week

Modified:
  head/sys/dev/usb/serial/u3g.c

Modified: head/sys/dev/usb/serial/u3g.c
==============================================================================
--- head/sys/dev/usb/serial/u3g.c	Fri Sep 12 22:20:07 2014	(r271491)
+++ head/sys/dev/usb/serial/u3g.c	Fri Sep 12 22:40:12 2014	(r271492)
@@ -75,6 +75,8 @@ SYSCTL_INT(_hw_usb_u3g, OID_AUTO, debug,
 #define	U3G_MAXPORTS		12
 #define	U3G_CONFIG_INDEX	0
 #define	U3G_BSIZE		2048
+#define	U3G_TXSIZE		(U3G_BSIZE / U3G_TXFRAMES)
+#define	U3G_TXFRAMES		4
 
 /* Eject methods; See also usb_quirks.h:UQ_MSC_EJECT_* */
 #define	U3GINIT_HUAWEI		1	/* Requires Huawei init command */
@@ -145,6 +147,7 @@ static const struct usb_config u3g_confi
 		.endpoint = UE_ADDR_ANY,
 		.direction = UE_DIR_OUT,
 		.bufsize = U3G_BSIZE,/* bytes */
+		.frames = U3G_TXFRAMES,
 		.flags = {.pipe_bof = 1,.force_short_xfer = 1,},
 		.callback = &u3g_write_callback,
 	},
@@ -1011,14 +1014,22 @@ u3g_write_callback(struct usb_xfer *xfer
 	struct ucom_softc *ucom = usbd_xfer_softc(xfer);
 	struct usb_page_cache *pc;
 	uint32_t actlen;
+	uint32_t frame;
 
 	switch (USB_GET_STATE(xfer)) {
 	case USB_ST_TRANSFERRED:
 	case USB_ST_SETUP:
 tr_setup:
-		pc = usbd_xfer_get_frame(xfer, 0);
-		if (ucom_get_data(ucom, pc, 0, U3G_BSIZE, &actlen)) {
-			usbd_xfer_set_frame_len(xfer, 0, actlen);
+		for (frame = 0; frame != U3G_TXFRAMES; frame++) {
+			usbd_xfer_set_frame_offset(xfer, frame * U3G_TXSIZE, frame);
+
+			pc = usbd_xfer_get_frame(xfer, frame);
+			if (ucom_get_data(ucom, pc, 0, U3G_TXSIZE, &actlen) == 0)
+				break;
+			usbd_xfer_set_frame_len(xfer, frame, actlen);
+		}
+		if (frame != 0) {
+			usbd_xfer_set_frames(xfer, frame);
 			usbd_transfer_submit(xfer);
 		}
 		break;