2014-12-18 11:52:50

by Chunyan Zhang

[permalink] [raw]
Subject: [PATCH 0/3] Changes the time type 'timeval' to 'Ktime'

This patch-set changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t) in imon.c, speedtest.c and torturetest.c, since 32-bit time
types will break in the year 2038.

This patch-set also introduces a reusable time difference function which
returns the difference in millisecond in ktime.h. The last two patches
of this patch-set will use this function, so they are dependent on the
first one.

Chunyan Zhang (3):
ktime.h: Introduce ktime_ms_delta
mtd: test: Replace timeval with ktime_t in speedtest.c and torturetest.c
media: rc: Replace timeval with ktime_t in imon.c

drivers/media/rc/imon.c | 49 +++++++++++----------------------------
drivers/mtd/tests/speedtest.c | 10 ++++----
drivers/mtd/tests/torturetest.c | 10 ++++----
include/linux/ktime.h | 5 ++++
4 files changed, 28 insertions(+), 46 deletions(-)

--
1.7.9.5


2014-12-18 11:53:02

by Chunyan Zhang

[permalink] [raw]
Subject: [PATCH 1/3] ktime.h: Introduce ktime_ms_delta

This patch introduces a reusable time difference function which returns
the difference in millisecond, as often used in some driver code, e.g.
mtd/test, media/rc, etc.

Signed-off-by: Chunyan Zhang <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
---
include/linux/ktime.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index c9d645a..891ea92 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -186,6 +186,11 @@ static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
return ktime_to_us(ktime_sub(later, earlier));
}

+static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier)
+{
+ return ktime_to_ms(ktime_sub(later, earlier));
+}
+
static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
{
return ktime_add_ns(kt, usec * NSEC_PER_USEC);
--
1.7.9.5

2014-12-18 11:53:12

by Chunyan Zhang

[permalink] [raw]
Subject: [PATCH 2/3] mtd: test: Replace timeval with ktime_t in speedtest.c and torturetest.c

This patch changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t), since 32-bit time types will break in the year 2038.

I use ktime_t instead of timeval to define 'start' and 'finish'
which are used to get the time for tow points.

This patch also changes do_gettimeofday() to ktime_get() accordingly,
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval, and the other reason is that ktime_get() uses
the monotonic clock.

This patch will use a new function 'ktime_ms_delta' which is introduced
in 1/3 of this patch-set to get the millisecond time difference.

Signed-off-by: Chunyan Zhang <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
---
drivers/mtd/tests/speedtest.c | 10 +++++-----
drivers/mtd/tests/torturetest.c | 10 +++++-----
2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/tests/speedtest.c b/drivers/mtd/tests/speedtest.c
index 5ee9f70..87a6e25 100644
--- a/drivers/mtd/tests/speedtest.c
+++ b/drivers/mtd/tests/speedtest.c
@@ -22,6 +22,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
+#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/err.h>
@@ -49,7 +50,7 @@ static int pgsize;
static int ebcnt;
static int pgcnt;
static int goodebcnt;
-static struct timeval start, finish;
+static ktime_t start, finish;

static int multiblock_erase(int ebnum, int blocks)
{
@@ -168,12 +169,12 @@ static int read_eraseblock_by_2pages(int ebnum)

static inline void start_timing(void)
{
- do_gettimeofday(&start);
+ start = ktime_get();
}

static inline void stop_timing(void)
{
- do_gettimeofday(&finish);
+ finish = ktime_get();
}

static long calc_speed(void)
@@ -181,8 +182,7 @@ static long calc_speed(void)
uint64_t k;
long ms;

- ms = (finish.tv_sec - start.tv_sec) * 1000 +
- (finish.tv_usec - start.tv_usec) / 1000;
+ ms = ktime_ms_delta(finish, start);
if (ms == 0)
return 0;
k = goodebcnt * (mtd->erasesize / 1024) * 1000;
diff --git a/drivers/mtd/tests/torturetest.c b/drivers/mtd/tests/torturetest.c
index eeab969..7e77ed4 100644
--- a/drivers/mtd/tests/torturetest.c
+++ b/drivers/mtd/tests/torturetest.c
@@ -26,6 +26,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
+#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/err.h>
@@ -79,18 +80,18 @@ static unsigned char *check_buf;
static unsigned int erase_cycles;

static int pgsize;
-static struct timeval start, finish;
+static ktime_t start, finish;

static void report_corrupt(unsigned char *read, unsigned char *written);

static inline void start_timing(void)
{
- do_gettimeofday(&start);
+ start = ktime_get();
}

static inline void stop_timing(void)
{
- do_gettimeofday(&finish);
+ finish = ktime_get();
}

/*
@@ -322,8 +323,7 @@ static int __init tort_init(void)
long ms;

stop_timing();
- ms = (finish.tv_sec - start.tv_sec) * 1000 +
- (finish.tv_usec - start.tv_usec) / 1000;
+ ms = ktime_ms_delta(finish, start);
pr_info("%08u erase cycles done, took %lu "
"milliseconds (%lu seconds)\n",
erase_cycles, ms, ms / 1000);
--
1.7.9.5

2014-12-18 11:53:23

by Chunyan Zhang

[permalink] [raw]
Subject: [PATCH 3/3] media: rc: Replace timeval with ktime_t in imon.c

This patch changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t), since 32-bit time types will break in the year 2038.

I use ktime_t instead of all uses of timeval in imon.c

This patch also changes do_gettimeofday() to ktime_get() accordingly,
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval, and the other reason is that ktime_get() uses
the monotonic clock.

This patch will use a new function 'ktime_ms_delta' which is introduced
in 1/3 of this patch-set to get the millisecond time difference.

Signed-off-by: Chunyan Zhang <[email protected]>
Acked-by: Mauro Carvalho Chehab <[email protected]>
---
drivers/media/rc/imon.c | 49 +++++++++++++----------------------------------
1 file changed, 13 insertions(+), 36 deletions(-)

diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index b8837dd..a1e91d5 100644
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -31,6 +31,7 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
@@ -41,7 +42,6 @@
#include <linux/usb/input.h>
#include <media/rc-core.h>

-#include <linux/time.h>
#include <linux/timer.h>

#define MOD_AUTHOR "Jarod Wilson <[email protected]>"
@@ -1158,29 +1158,6 @@ out:
return retval;
}

-static inline int tv2int(const struct timeval *a, const struct timeval *b)
-{
- int usecs = 0;
- int sec = 0;
-
- if (b->tv_usec > a->tv_usec) {
- usecs = 1000000;
- sec--;
- }
-
- usecs += a->tv_usec - b->tv_usec;
-
- sec += a->tv_sec - b->tv_sec;
- sec *= 1000;
- usecs /= 1000;
- sec += usecs;
-
- if (sec < 0)
- sec = 1000;
-
- return sec;
-}
-
/**
* The directional pad behaves a bit differently, depending on whether this is
* one of the older ffdc devices or a newer device. Newer devices appear to
@@ -1191,16 +1168,16 @@ static inline int tv2int(const struct timeval *a, const struct timeval *b)
*/
static int stabilize(int a, int b, u16 timeout, u16 threshold)
{
- struct timeval ct;
- static struct timeval prev_time = {0, 0};
- static struct timeval hit_time = {0, 0};
+ ktime_t ct;
+ static ktime_t prev_time;
+ static ktime_t hit_time;
static int x, y, prev_result, hits;
int result = 0;
- int msec, msec_hit;
+ long msec, msec_hit;

- do_gettimeofday(&ct);
- msec = tv2int(&ct, &prev_time);
- msec_hit = tv2int(&ct, &hit_time);
+ ct = ktime_get();
+ msec = ktime_ms_delta(ct, prev_time);
+ msec_hit = ktime_ms_delta(ct, hit_time);

if (msec > 100) {
x = 0;
@@ -1596,9 +1573,9 @@ static void imon_incoming_packet(struct imon_context *ictx,
int i;
u64 scancode;
int press_type = 0;
- int msec;
- struct timeval t;
- static struct timeval prev_time = { 0, 0 };
+ long msec;
+ ktime_t t;
+ static ktime_t prev_time;
u8 ktype;

/* filter out junk data on the older 0xffdc imon devices */
@@ -1692,10 +1669,10 @@ static void imon_incoming_packet(struct imon_context *ictx,
/* Only panel type events left to process now */
spin_lock_irqsave(&ictx->kc_lock, flags);

- do_gettimeofday(&t);
+ t = ktime_get();
/* KEY_MUTE repeats from knob need to be suppressed */
if (ictx->kc == KEY_MUTE && ictx->kc == ictx->last_keycode) {
- msec = tv2int(&t, &prev_time);
+ msec = ktime_ms_delta(t, prev_time);
if (msec < ictx->idev->rep[REP_DELAY]) {
spin_unlock_irqrestore(&ictx->kc_lock, flags);
return;
--
1.7.9.5