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authorAbhilash Jindal <klock.android@gmail.com>2015-08-11 12:22:57 -0300
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-08-16 13:29:59 -0300
commit82fde1a98eb9866347a1d3543fac4ab9a69aeb7d (patch)
tree2ba862a50bb000695983bf779c34b5cdf81d3bae /drivers/media/pci
parente4d45dd81e67f9fe0e1af44bddd53c3d4eb061ea (diff)
[media] bt8xxx: Use monotonic time
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>
Diffstat (limited to 'drivers/media/pci')
-rw-r--r--drivers/media/pci/bt8xx/bttv-input.c21
-rw-r--r--drivers/media/pci/bt8xx/bttvp.h2
2 files changed, 9 insertions, 14 deletions
diff --git a/drivers/media/pci/bt8xx/bttv-input.c b/drivers/media/pci/bt8xx/bttv-input.c
index 67c8d6b2c335..a75c53da224a 100644
--- a/drivers/media/pci/bt8xx/bttv-input.c
+++ b/drivers/media/pci/bt8xx/bttv-input.c
@@ -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",
diff --git a/drivers/media/pci/bt8xx/bttvp.h b/drivers/media/pci/bt8xx/bttvp.h
index a444cfb35c0b..31bf79d3b0d2 100644
--- a/drivers/media/pci/bt8xx/bttvp.h
+++ b/drivers/media/pci/bt8xx/bttvp.h
@@ -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 */
};

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