Em Sat, 29 Dec 2012 14:01:57 +0100
Alexandre Lissy <lissyx+mozfr@xxxxxxxxxxxxxxxxx> escreveu:
> From cca7718a9902a4d5cffbf158b5853980a08ef930 Mon Sep 17 00:00:00 2001
> From: Alexandre Lissy <alexandrelissy@xxxxxxx>
> Date: Sun, 2 Sep 2012 20:35:20 +0200
> Subject: [PATCH] fix: iMon Knob event interpretation issues
>
> Events for the iMon Knob pad where not correctly interpreted, 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.
>
> Signed-off-by: Alexandre Lissy <alexandrelissy@xxxxxxx>
> ---
> drivers/media/rc/imon.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
> index 5dd0386..9d30ca9 100644
> --- a/drivers/media/rc/imon.c
> +++ b/drivers/media/rc/imon.c
> @@ -1225,7 +1225,7 @@ static u32 imon_panel_key_lookup(u64 code)
> 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;
(c/c Jarod, as he is the maintainer of this driver)
That looks weird, as, AFAIKT "char" is signed. Are you sure that this fix
is correct?
If so, maybe this could be a gcc-version-specific bug. What gcc version are
you using?
Btw, we generally use "s8" type for signed 8bit integers inside the Kernel.
> u8 right_shift = 1;
> bool mouse_input = true;
> int dir = 0;
> @@ -1301,7 +1301,7 @@ static void imon_touch_event(struct imon_context *ictx, unsigned char *buf)
> 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;
--
Cheers,
Mauro
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