commit 24dec5dabfcc1d424d7bc86d393d31f57ebcc975
author Alexandre Lissy <alexandrelissy@free.fr> Sun Sep 02 15:35:20 2012 -0300
committer Mauro Carvalho Chehab <mchehab@redhat.com> Fri Feb 01 07:13:59 2013 -0200
tree 16accd08e370abf4de504ebbb4d12319dc7e6b7e
parent a32f7d1ad3744914273c6907204c2ab3b5d496a0

[media] imon: fix Knob event interpretation issues on ARM

Events for the iMon Knob pad where not correctly interpreted on ARM,
resulting in buggy mouse movements (cursor going straight out of the
screen), key pad only generating KEY_RIGHT and KEY_DOWN events.
A reproducer is:
int main(int argc, char ** argv)
{
        char rel_x = 0x00; printf("rel_x:%d @%s:%d\n", rel_x, __FILE__, __LINE__);
        rel_x = 0x0f; printf("rel_x:%d @%s:%d\n", rel_x, __FILE__, __LINE__);
        rel_x |= ~0x0f; printf("rel_x:%d @%s:%d\n", rel_x, __FILE__, __LINE__);
        return 0;
}
(running on x86 or amd64)
$ ./test
rel_x:0 @test.c:6
rel_x:15 @test.c:7
rel_x:-1 @test.c:8
(running on armv6)
rel_x:0 @test.c:6
rel_x:15 @test.c:7
rel_x:255 @test.c:8
Forcing the rel_x and rel_y variables as signed char fixes the issue.

Reference: http://www.arm.linux.org.uk/docs/faqs/signedchar.php

Signed-off-by: Alexandre Lissy <alexandrelissy@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/rc/imon.c

diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index 78d109b..dec203b 100644
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -1221,7 +1221,7 @@
 static bool imon_mouse_event(struct imon_context *ictx,
 			     unsigned char *buf, int len)
 {
-	char rel_x = 0x00, rel_y = 0x00;
+	signed char rel_x = 0x00, rel_y = 0x00;
 	u8 right_shift = 1;
 	bool mouse_input = true;
 	int dir = 0;
@@ -1297,7 +1297,7 @@
 static void imon_pad_to_keys(struct imon_context *ictx, unsigned char *buf)
 {
 	int dir = 0;
-	char rel_x = 0x00, rel_y = 0x00;
+	signed char rel_x = 0x00, rel_y = 0x00;
 	u16 timeout, threshold;
 	u32 scancode = KEY_RESERVED;
 	unsigned long flags;