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[media] bt8xxx: Use monotonic time

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Wall time obtained from do_gettimeofday is susceptible to sudden jumps due to
user setting the time or due to NTP.

Monotonic time is constantly increasing time better suited for comparing two
timestamps.

Signed-off-by: Abhilash Jindal <klock.android@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Abhilash Jindal 2015-08-11 12:22:57 -03:00 committed by Mauro Carvalho Chehab
parent e4d45dd81e
commit 82fde1a98e
2 changed files with 9 additions and 14 deletions
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21
drivers/media/pci/bt8xx/bttv-input.c
View file

@ -194,21 +194,18 @@ static u32 bttv_rc5_decode(unsigned int code)
static void bttv_rc5_timer_end(unsigned long data)
{
struct bttv_ir *ir = (struct bttv_ir *)data;
struct timeval tv;
ktime_t tv;
u32 gap, rc5, scancode;
u8 toggle, command, system;
/* get time */
do_gettimeofday(&tv);
tv = ktime_get();
gap = ktime_to_us(ktime_sub(tv, ir->base_time));
/* avoid overflow with gap >1s */
if (tv.tv_sec - ir->base_time.tv_sec > 1) {
if (gap > USEC_PER_SEC) {
gap = 200000;
} else {
gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
tv.tv_usec - ir->base_time.tv_usec;
}
/* signal we're ready to start a new code */
ir->active = false;
@ -249,7 +246,7 @@ static void bttv_rc5_timer_end(unsigned long data)
static int bttv_rc5_irq(struct bttv *btv)
{
struct bttv_ir *ir = btv->remote;
struct timeval tv;
ktime_t tv;
u32 gpio;
u32 gap;
unsigned long current_jiffies;
@ -259,14 +256,12 @@ static int bttv_rc5_irq(struct bttv *btv)
/* get time of bit */
current_jiffies = jiffies;
do_gettimeofday(&tv);
tv = ktime_get();
gap = ktime_to_us(ktime_sub(tv, ir->base_time));
/* avoid overflow with gap >1s */
if (tv.tv_sec - ir->base_time.tv_sec > 1) {
if (gap > USEC_PER_SEC) {
gap = 200000;
} else {
gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
tv.tv_usec - ir->base_time.tv_usec;
}
dprintk("RC5 IRQ: gap %d us for %s\n",

2
drivers/media/pci/bt8xx/bttvp.h
View file

@ -140,7 +140,7 @@ struct bttv_ir {
bool rc5_gpio; /* Is RC5 legacy GPIO enabled? */
u32 last_bit; /* last raw bit seen */
u32 code; /* raw code under construction */
struct timeval base_time; /* time of last seen code */
ktime_t base_time; /* time of last seen code */
bool active; /* building raw code */
};