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can: peak_usb: use ktime_t consistently

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This changes the calculation of the timestamps to use ktime_t
instead of struct timeval as the base. This gets rid of one
of the few remaining users of the deprecated ktime_to_timeval()
and timeval_to_ktime() helpers.

The code should also get more efficient, as we have now removed
all of the divisions.

I have left the cut-off for resetting the counters as 4.200
seconds, in order to leave the behavior unchanged otherwise.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Arnd Bergmann 2017-11-03 17:31:37 +01:00 committed by Marc Kleine-Budde
parent d5888a1e75
commit aa4f3c660a
2 changed files with 15 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
drivers/net/can/usb/peak_usb/pcan_usb_core.c
View File

@ -80,21 +80,6 @@ void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
}
}
static void peak_usb_add_us(struct timeval *tv, u32 delta_us)
{
/* number of s. to add to final time */
u32 delta_s = delta_us / 1000000;
delta_us -= delta_s * 1000000;
tv->tv_usec += delta_us;
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
delta_s++;
}
tv->tv_sec += delta_s;
}
/*
* sometimes, another now may be more recent than current one...
*/
@ -103,7 +88,7 @@ void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
time_ref->ts_dev_2 = ts_now;
/* should wait at least two passes before computing */
if (time_ref->tv_host.tv_sec > 0) {
if (ktime_to_ns(time_ref->tv_host) > 0) {
u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
@ -118,26 +103,26 @@ void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
*/
void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
{
if (time_ref->tv_host_0.tv_sec == 0) {
if (ktime_to_ns(time_ref->tv_host_0) == 0) {
/* use monotonic clock to correctly compute further deltas */
time_ref->tv_host_0 = ktime_to_timeval(ktime_get());
time_ref->tv_host.tv_sec = 0;
time_ref->tv_host_0 = ktime_get();
time_ref->tv_host = ktime_set(0, 0);
} else {
/*
* delta_us should not be >= 2^32 => delta_s should be < 4294
* delta_us should not be >= 2^32 => delta should be < 4294s
* handle 32-bits wrapping here: if count of s. reaches 4200,
* reset counters and change time base
*/
if (time_ref->tv_host.tv_sec != 0) {
u32 delta_s = time_ref->tv_host.tv_sec
- time_ref->tv_host_0.tv_sec;
if (delta_s > 4200) {
if (ktime_to_ns(time_ref->tv_host)) {
ktime_t delta = ktime_sub(time_ref->tv_host,
time_ref->tv_host_0);
if (ktime_to_ns(delta) > (4200ull * NSEC_PER_SEC)) {
time_ref->tv_host_0 = time_ref->tv_host;
time_ref->ts_total = 0;
}
}
time_ref->tv_host = ktime_to_timeval(ktime_get());
time_ref->tv_host = ktime_get();
time_ref->tick_count++;
}
@ -146,13 +131,12 @@ void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
}
/*
* compute timeval according to current ts and time_ref data
* compute time according to current ts and time_ref data
*/
void peak_usb_get_ts_time(struct peak_time_ref *time_ref, u32 ts, ktime_t *time)
{
/* protect from getting timeval before setting now */
if (time_ref->tv_host.tv_sec > 0) {
struct timeval tv;
/* protect from getting time before setting now */
if (ktime_to_ns(time_ref->tv_host)) {
u64 delta_us;
delta_us = ts - time_ref->ts_dev_2;
@ -164,9 +148,7 @@ void peak_usb_get_ts_time(struct peak_time_ref *time_ref, u32 ts, ktime_t *time)
delta_us *= time_ref->adapter->us_per_ts_scale;
delta_us >>= time_ref->adapter->us_per_ts_shift;
tv = time_ref->tv_host_0;
peak_usb_add_us(&tv, (u32)delta_us);
*time = timeval_to_ktime(tv);
*time = ktime_add_us(time_ref->tv_host_0, delta_us);
} else {
*time = ktime_get();
}

2
drivers/net/can/usb/peak_usb/pcan_usb_core.h
View File

@ -96,7 +96,7 @@ extern const struct peak_usb_adapter pcan_usb_pro_fd;
extern const struct peak_usb_adapter pcan_usb_x6;
struct peak_time_ref {
struct timeval tv_host_0, tv_host;
ktime_t tv_host_0, tv_host;
u32 ts_dev_1, ts_dev_2;
u64 ts_total;
u32 tick_count;