AcoSail/kernel_optimize_test
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[media] zoran: 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 12:09:49 -03:00 committed by Mauro Carvalho Chehab
parent 8f7a5f462a
commit e4d45dd81e
1 changed files with 5 additions and 13 deletions
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18
drivers/media/pci/zoran/zoran_device.c
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@ -31,6 +31,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/ktime.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
@ -181,20 +182,11 @@ dump_guests (struct zoran *zr)
}
}
static inline unsigned long
get_time (void)
{
struct timeval tv;
do_gettimeofday(&tv);
return (1000000 * tv.tv_sec + tv.tv_usec);
}
void
detect_guest_activity (struct zoran *zr)
{
int timeout, i, j, res, guest[8], guest0[8], change[8][3];
unsigned long t0, t1;
ktime_t t0, t1;
dump_guests(zr);
printk(KERN_INFO "%s: Detecting guests activity, please wait...\n",
@ -205,15 +197,15 @@ detect_guest_activity (struct zoran *zr)
timeout = 0;
j = 0;
t0 = get_time();
t0 = ktime_get();
while (timeout < 10000) {
udelay(10);
timeout++;
for (i = 1; (i < 8) && (j < 8); i++) {
res = post_office_read(zr, i, 0);
if (res != guest[i]) {
t1 = get_time();
change[j][0] = (t1 - t0);
t1 = ktime_get();
change[j][0] = ktime_to_us(ktime_sub(t1, t0));
t0 = t1;
change[j][1] = i;
change[j][2] = res;