commit: 74b89e8a3625c17c7452532dfb997ac4f1a38751
From: David Herrmann <[email protected]>
Date: Tue, 8 May 2012 16:52:31 +0200
Subject: HID: wiimote: Fix IR data parser

We incorrectly parse incoming IR data. The extra byte contains the upper
bits and not the lower bits of the x/y coordinates. User-space expects
absolute position data from us so this patch does not break existing
applications. On the contrary, it extends the virtual view and fixes
garbage reports for margin areas of the virtual screen.

Cc: [email protected]
Reported-by: Peter Bukovsky <[email protected]>
Signed-off-by: David Herrmann <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
---
 drivers/hid/hid-wiimote-core.c |   16 +++++-----------
 1 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/hid/hid-wiimote-core.c b/drivers/hid/hid-wiimote-core.c
index cac3589..84e2fbe 100644
--- a/drivers/hid/hid-wiimote-core.c
+++ b/drivers/hid/hid-wiimote-core.c
@@ -769,7 +769,7 @@ static void __ir_to_input(struct wiimote_data *wdata, const 
__u8 *ir,
 
        /*
         * Basic IR data is encoded into 3 bytes. The first two bytes are the
-        * upper 8 bit of the X/Y data, the 3rd byte contains the lower 2 bits
+        * lower 8 bit of the X/Y data, the 3rd byte contains the upper 2 bits
         * of both.
         * If data is packed, then the 3rd byte is put first and slightly
         * reordered. This allows to interleave packed and non-packed data to
@@ -778,17 +778,11 @@ static void __ir_to_input(struct wiimote_data *wdata, 
const __u8 *ir,
         */
 
        if (packed) {
-               x = ir[1] << 2;
-               y = ir[2] << 2;
-
-               x |= ir[0] & 0x3;
-               y |= (ir[0] >> 2) & 0x3;
+               x = ir[1] | ((ir[0] & 0x03) << 8);
+               y = ir[2] | ((ir[0] & 0x0c) << 6);
        } else {
-               x = ir[0] << 2;
-               y = ir[1] << 2;
-
-               x |= (ir[2] >> 4) & 0x3;
-               y |= (ir[2] >> 6) & 0x3;
+               x = ir[0] | ((ir[2] & 0x30) << 4);
+               y = ir[1] | ((ir[2] & 0xc0) << 2);
        }
 
        input_report_abs(wdata->ir, xid, x);
-- 
1.7.3.4
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