Input: wacom - don't use on-stack memory for report buffers

Tested-by: Martin Capitanio <martin@capitanio.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 29 insertions, 14 deletions

diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index a9d5031b855e..ea30c983a33e 100644
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -388,6 +388,32 @@ static int wacom_parse_hid(struct usb_interface *intf, struct hid_descriptor *hi
         return result;
 }
 
+static int wacom_query_tablet_data(struct usb_interface *intf)
+{
+        unsigned char *rep_data;
+        int limit = 0;
+        int error;
+
+        rep_data = kmalloc(2, GFP_KERNEL);
+        if (!rep_data)
+                return -ENOMEM;
+
+        do {
+                rep_data[0] = 2;
+                rep_data[1] = 2;
+                error = usb_set_report(intf, WAC_HID_FEATURE_REPORT,
+                                        2, rep_data, 2);
+                if (error >= 0)
+                        error = usb_get_report(intf,
+                                                WAC_HID_FEATURE_REPORT, 2,
+                                                rep_data, 2);
+        } while ((error < 0 || rep_data[1] != 2) && limit++ < 5);
+
+        kfree(rep_data);
+
+        return error < 0 ? error : 0;
+}
+
 static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
         struct usb_device *dev = interface_to_usbdev(intf);
@@ -398,7 +424,6 @@ static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *i
         struct wacom_features *features;
         struct input_dev *input_dev;
         int error = -ENOMEM;
-        char rep_data[2], limit = 0;
         struct hid_descriptor *hid_desc;
 
         wacom = kzalloc(sizeof(struct wacom), GFP_KERNEL);
@@ -489,20 +514,10 @@ static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *i
 
         /*
          * Ask the tablet to report tablet data if it is not a Tablet PC.
-         * Repeat until it succeeds
+         * Note that if query fails it is not a hard failure.
          */
-        if (wacom_wac->features->type != TABLETPC) {
-                do {
-                        rep_data[0] = 2;
-                        rep_data[1] = 2;
-                        error = usb_set_report(intf, WAC_HID_FEATURE_REPORT,
-                                                2, rep_data, 2);
-                        if (error >= 0)
-                                error = usb_get_report(intf,
-                                                WAC_HID_FEATURE_REPORT, 2,
-                                                rep_data, 2);
-                } while ((error < 0 || rep_data[1] != 2) && limit++ < 5);
-        }
+        if (wacom_wac->features->type != TABLETPC)
+                wacom_query_tablet_data(intf);
 
         usb_set_intfdata(intf, wacom);
         return 0;