'struct timeval last_tv' is used to get the time of last signal change
and 'struct timeval last_intr_tv' is used to get the time of last UART
interrupt.
32-bit systems using 'struct timeval' will break in the year 2038, so we
have to replace that code with more appropriate types.
Here struct timeval is replaced with ktime_t.
Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@xxxxxxxxx>
---
Changes in v3:
- as John suggested delta function is changed to inline function,
checkpatch signals a warning to change min to min_t. Is it a false
positive?
- change variable names.
Changes in v2:
- change subject line
drivers/staging/media/lirc/lirc_sir.c | 51 +++++++++++++----------------------
1 file changed, 18 insertions(+), 33 deletions(-)
diff --git a/drivers/staging/media/lirc/lirc_sir.c b/drivers/staging/media/lirc/lirc_sir.c
index 29087f6..c98c486 100644
--- a/drivers/staging/media/lirc/lirc_sir.c
+++ b/drivers/staging/media/lirc/lirc_sir.c
@@ -44,7 +44,7 @@
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/serial_reg.h>
-#include <linux/time.h>
+#include <linux/ktime.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/wait.h>
@@ -127,9 +127,9 @@ static int threshold = 3;
static DEFINE_SPINLOCK(timer_lock);
static struct timer_list timerlist;
/* time of last signal change detected */
-static struct timeval last_tv = {0, 0};
+static ktime_t last;
/* time of last UART data ready interrupt */
-static struct timeval last_intr_tv = {0, 0};
+static ktime_t last_intr_time;
static int last_value;
static DECLARE_WAIT_QUEUE_HEAD(lirc_read_queue);
@@ -400,18 +400,11 @@ static void drop_chrdev(void)
}
/* SECTION: Hardware */
-static long delta(struct timeval *tv1, struct timeval *tv2)
+static inline long delta(ktime_t t1, ktime_t t2)
{
- unsigned long deltv;
-
- deltv = tv2->tv_sec - tv1->tv_sec;
- if (deltv > 15)
- deltv = 0xFFFFFF;
- else
- deltv = deltv*1000000 +
- tv2->tv_usec -
- tv1->tv_usec;
- return deltv;
+ /* return the delta in 32bit usecs, but cap to UINTMAX in case the
+ * delta is greater then 32bits */
+ return (long) min((unsigned int) ktime_us_delta(t1, t2), UINT_MAX);
}
static void sir_timeout(unsigned long data)
@@ -432,12 +425,12 @@ static void sir_timeout(unsigned long data)
/* clear unread bits in UART and restart */
outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
/* determine 'virtual' pulse end: */
- pulse_end = delta(&last_tv, &last_intr_tv);
+ pulse_end = delta(last, last_intr_time);
dev_dbg(driver.dev, "timeout add %d for %lu usec\n",
last_value, pulse_end);
add_read_queue(last_value, pulse_end);
last_value = 0;
- last_tv = last_intr_tv;
+ last = last_intr_time;
}
spin_unlock_irqrestore(&timer_lock, flags);
}
@@ -445,7 +438,7 @@ static void sir_timeout(unsigned long data)
static irqreturn_t sir_interrupt(int irq, void *dev_id)
{
unsigned char data;
- struct timeval curr_tv;
+ ktime_t curr_time;
static unsigned long deltv;
unsigned long deltintrtv;
unsigned long flags;
@@ -471,9 +464,9 @@ static irqreturn_t sir_interrupt(int irq, void *dev_id)
do {
del_timer(&timerlist);
data = inb(io + UART_RX);
- do_gettimeofday(&curr_tv);
- deltv = delta(&last_tv, &curr_tv);
- deltintrtv = delta(&last_intr_tv, &curr_tv);
+ curr_time = ktime_get();
+ deltv = delta(last, curr_time);
+ deltintrtv = delta(last_intr_time, curr_time);
dev_dbg(driver.dev, "t %lu, d %d\n",
deltintrtv, (int)data);
/*
@@ -488,10 +481,7 @@ static irqreturn_t sir_interrupt(int irq, void *dev_id)
deltv -
deltintrtv);
last_value = 0;
- last_tv.tv_sec =
- last_intr_tv.tv_sec;
- last_tv.tv_usec =
- last_intr_tv.tv_usec;
+ last = last_intr_time;
deltv = deltintrtv;
}
}
@@ -504,16 +494,11 @@ static irqreturn_t sir_interrupt(int irq, void *dev_id)
add_read_queue(last_value,
deltv-TIME_CONST);
last_value = data;
- last_tv = curr_tv;
- if (last_tv.tv_usec >= TIME_CONST) {
- last_tv.tv_usec -= TIME_CONST;
- } else {
- last_tv.tv_sec--;
- last_tv.tv_usec += 1000000 -
- TIME_CONST;
- }
+ last = curr_time;
+ last = ktime_sub_us(last,
+ TIME_CONST);
}
- last_intr_tv = curr_tv;
+ last_intr_time = curr_time;
if (data) {
/*
* start timer for end of
--
1.9.1
--
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