1 files changed, 33 insertions, 22 deletions

diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c
index 19055e7381f8..63f9664a066f 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -11,6 +11,7 @@
  *  - DMC TSC-10/25
  *  - IRTOUCHSYSTEMS/UNITOP
  *  - IdealTEK URTC1000
+ *  - General Touch
  *  - GoTop Super_Q2/GogoPen/PenPower tablets
  *
  * Copyright (C) 2004-2007 by Daniel Ritz <daniel.ritz@gmx.ch>
@@ -50,7 +51,7 @@
 #include <linux/usb/input.h>
 
 
-#define DRIVER_VERSION          "v0.5"
+#define DRIVER_VERSION          "v0.6"
 #define DRIVER_AUTHOR           "Daniel Ritz <daniel.ritz@gmx.ch>"
 #define DRIVER_DESC             "USB Touchscreen Driver"
 
@@ -65,17 +66,21 @@ struct usbtouch_device_info {
         int min_yc, max_yc;
         int min_press, max_press;
         int rept_size;
-        int flags;
 
         void (*process_pkt) (struct usbtouch_usb *usbtouch, unsigned char *pkt, int len);
+
+        /*
+         * used to get the packet len. possible return values:
+         * > 0: packet len
+         * = 0: skip one byte
+         * < 0: -return value more bytes needed
+         */
         int  (*get_pkt_len) (unsigned char *pkt, int len);
+
         int  (*read_data)   (struct usbtouch_usb *usbtouch, unsigned char *pkt);
         int  (*init)        (struct usbtouch_usb *usbtouch);
 };
 
-#define USBTOUCH_FLG_BUFFER     0x01
-
-
 /* a usbtouch device */
 struct usbtouch_usb {
         unsigned char *data;
@@ -94,15 +99,6 @@ struct usbtouch_usb {
 };
 
 
-#if defined(CONFIG_TOUCHSCREEN_USB_EGALAX) || defined(CONFIG_TOUCHSCREEN_USB_ETURBO) || defined(CONFIG_TOUCHSCREEN_USB_IDEALTEK)
-#define MULTI_PACKET
-#endif
-
-#ifdef MULTI_PACKET
-static void usbtouch_process_multi(struct usbtouch_usb *usbtouch,
-                                   unsigned char *pkt, int len);
-#endif
-
 /* device types */
 enum {
         DEVTPYE_DUMMY = -1,
@@ -186,6 +182,10 @@ static struct usb_device_id usbtouch_devices[] = {
 
 #ifdef CONFIG_TOUCHSCREEN_USB_EGALAX
 
+#ifndef MULTI_PACKET
+#define MULTI_PACKET
+#endif
+
 #define EGALAX_PKT_TYPE_MASK            0xFE
 #define EGALAX_PKT_TYPE_REPT            0x80
 #define EGALAX_PKT_TYPE_DIAG            0x0A
@@ -323,6 +323,9 @@ static int itm_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
  * eTurboTouch part
  */
 #ifdef CONFIG_TOUCHSCREEN_USB_ETURBO
+#ifndef MULTI_PACKET
+#define MULTI_PACKET
+#endif
 static int eturbo_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
 {
         unsigned int shift;
@@ -461,6 +464,9 @@ static int irtouch_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
  * IdealTEK URTC1000 Part
  */
 #ifdef CONFIG_TOUCHSCREEN_USB_IDEALTEK
+#ifndef MULTI_PACKET
+#define MULTI_PACKET
+#endif
 static int idealtek_get_pkt_len(unsigned char *buf, int len)
 {
         if (buf[0] & 0x80)
@@ -525,6 +531,11 @@ static int gotop_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
 /*****************************************************************************
  * the different device descriptors
  */
+#ifdef MULTI_PACKET
+static void usbtouch_process_multi(struct usbtouch_usb *usbtouch,
+                                   unsigned char *pkt, int len);
+#endif
+
 static struct usbtouch_device_info usbtouch_dev_info[] = {
 #ifdef CONFIG_TOUCHSCREEN_USB_EGALAX
         [DEVTYPE_EGALAX] = {
@@ -533,7 +544,6 @@ static struct usbtouch_device_info usbtouch_dev_info[] = {
                 .min_yc         = 0x0,
                 .max_yc         = 0x07ff,
                 .rept_size      = 16,
-                .flags          = USBTOUCH_FLG_BUFFER,
                 .process_pkt    = usbtouch_process_multi,
                 .get_pkt_len    = egalax_get_pkt_len,
                 .read_data      = egalax_read_data,
@@ -582,7 +592,6 @@ static struct usbtouch_device_info usbtouch_dev_info[] = {
                 .min_yc         = 0x0,
                 .max_yc         = 0x07ff,
                 .rept_size      = 8,
-                .flags          = USBTOUCH_FLG_BUFFER,
                 .process_pkt    = usbtouch_process_multi,
                 .get_pkt_len    = eturbo_get_pkt_len,
                 .read_data      = eturbo_read_data,
@@ -630,7 +639,6 @@ static struct usbtouch_device_info usbtouch_dev_info[] = {
                 .min_yc         = 0x0,
                 .max_yc         = 0x0fff,
                 .rept_size      = 8,
-                .flags          = USBTOUCH_FLG_BUFFER,
                 .process_pkt    = usbtouch_process_multi,
                 .get_pkt_len    = idealtek_get_pkt_len,
                 .read_data      = idealtek_read_data,
@@ -738,11 +746,14 @@ static void usbtouch_process_multi(struct usbtouch_usb *usbtouch,
         pos = 0;
         while (pos < buf_len) {
                 /* get packet len */
-                pkt_len = usbtouch->type->get_pkt_len(buffer + pos, len);
+                pkt_len = usbtouch->type->get_pkt_len(buffer + pos,
+                                                        buf_len - pos);
 
-                /* unknown packet: drop everything */
-                if (unlikely(!pkt_len))
-                        goto out_flush_buf;
+                /* unknown packet: skip one byte */
+                if (unlikely(!pkt_len)) {
+                        pos++;
+                        continue;
+                }
 
                 /* full packet: process */
                 if (likely((pkt_len > 0) && (pkt_len <= buf_len - pos))) {
@@ -857,7 +868,7 @@ static int usbtouch_probe(struct usb_interface *intf,
         if (!usbtouch->data)
                 goto out_free;
 
-        if (type->flags & USBTOUCH_FLG_BUFFER) {
+        if (type->get_pkt_len) {
                 usbtouch->buffer = kmalloc(type->rept_size, GFP_KERNEL);
                 if (!usbtouch->buffer)
                         goto out_free_buffers;