staging: vt6656: [BUG] Fix for TX USB resets from vendors driver.

This fixes resets on heavy TX data traffic.

Vendor driver
VT6656_Linux_src_v1.21.03_x86_11.04.zip
http://www.viaembedded.com/servlet/downloadSvl?id=1890&download_file_id=14704
This is GPL-licensed code.

original code
BBbVT3184Init
...
//2007-0725, RobertChang add, Enable Squelch detect reset option(SQ_RST_Opt), USB (register4, bit1)
CONTROLnsRequestIn(pDevice,
                                 MESSAGE_TYPE_READ,
                                 (WORD)0x600+4,     // USB's Reg4's bit1
                                 MESSAGE_REQUEST_MEM,
                                 1,
                                 (PBYTE) &byData);
byData = byData|2 ;
CONTROLnsRequestOut(pDevice,
                              MESSAGE_TYPE_WRITE,
                              (WORD)0x600+4,     // USB's Reg4's bit1
                              MESSAGE_REQUEST_MEM,
                              1,
                              (PBYTE) &byData);

return TRUE;//ntStatus;
....

A back port patch is needed for kernels less than 3.10.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/baseband.c

@@ -939,6 +939,7 @@ int BBbVT3184Init(struct vnt_private *pDevice)
     u8 *                   pbyAgc;
     u16                    wLengthAgc;
     u8                    abyArray[256];
+	u8 data;
 
     ntStatus = CONTROLnsRequestIn(pDevice,
                                   MESSAGE_TYPE_READ,
@@ -1104,6 +1105,16 @@ else {
     ControlvWriteByte(pDevice,MESSAGE_REQUEST_BBREG,0x0D,0x01);
 
     RFbRFTableDownload(pDevice);
+
+	/* Fix for TX USB resets from vendors driver */
+	CONTROLnsRequestIn(pDevice, MESSAGE_TYPE_READ, USB_REG4,
+		MESSAGE_REQUEST_MEM, sizeof(data), &data);
+
+	data |= 0x2;
+
+	CONTROLnsRequestOut(pDevice, MESSAGE_TYPE_WRITE, USB_REG4,
+		MESSAGE_REQUEST_MEM, sizeof(data), &data);
+
     return true;//ntStatus;
 }
 

drivers/staging/vt6656/rndis.h

@@ -66,6 +66,8 @@
 
 #define VIAUSB20_PACKET_HEADER          0x04
 
+#define USB_REG4	0x604
+
 typedef struct _CMD_MESSAGE
 {
     u8        byData[256];