struct timeval uses a 32-bit seconds representation which will
overflow in the year 2038 and beyond. This patch replaces
the usage of struct timeval with ktime_t which is a 64-bit
timestamp and is year 2038 safe.
This patch is part of a larger attempt to remove all instances
of 32-bit timekeeping variables (timeval, timespec, time_t)
which are not year 2038 safe, from the kernel.

Signed-off-by: Tina Ruchandani <ruchandani.t...@gmail.com>
Suggested-by: Arnd Bergmann <ar...@arndb.de>

--
Changes in v3:
- Clean up commit message.
- Use ktime_us_delta which is more concise than the combination
of ktime_sub and ktime_to_us
Changes in v2:
- Use the more concise ktime_us_delta
- Preserve the waketime argument in dvb_frontend_sleep_until as
a pointer, fixes bug introduced in v1 of the patch where the caller
doesn't get its timestamp modified.

Signed-off-by: Tina Ruchandani <ruchandani.t...@gmail.com>
---
 drivers/media/dvb-core/dvb_frontend.c | 41 ++++++++++-------------------------
 drivers/media/dvb-core/dvb_frontend.h |  3 +--
 drivers/media/dvb-frontends/stv0299.c | 12 +++++-----
 3 files changed, 19 insertions(+), 37 deletions(-)

diff --git a/drivers/media/dvb-core/dvb_frontend.c 
b/drivers/media/dvb-core/dvb_frontend.c
index 882ca41..69be73c 100644
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -40,6 +40,7 @@
 #include <linux/freezer.h>
 #include <linux/jiffies.h>
 #include <linux/kthread.h>
+#include <linux/ktime.h>
 #include <asm/processor.h>
 
 #include "dvb_frontend.h"
@@ -889,42 +890,21 @@ static void dvb_frontend_stop(struct dvb_frontend *fe)
                                fepriv->thread);
 }
 
-s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime)
-{
-       return ((curtime.tv_usec < lasttime.tv_usec) ?
-               1000000 - lasttime.tv_usec + curtime.tv_usec :
-               curtime.tv_usec - lasttime.tv_usec);
-}
-EXPORT_SYMBOL(timeval_usec_diff);
-
-static inline void timeval_usec_add(struct timeval *curtime, u32 add_usec)
-{
-       curtime->tv_usec += add_usec;
-       if (curtime->tv_usec >= 1000000) {
-               curtime->tv_usec -= 1000000;
-               curtime->tv_sec++;
-       }
-}
-
 /*
  * Sleep until gettimeofday() > waketime + add_usec
  * This needs to be as precise as possible, but as the delay is
  * usually between 2ms and 32ms, it is done using a scheduled msleep
  * followed by usleep (normally a busy-wait loop) for the remainder
  */
-void dvb_frontend_sleep_until(struct timeval *waketime, u32 add_usec)
+void dvb_frontend_sleep_until(ktime_t *waketime, u32 add_usec)
 {
-       struct timeval lasttime;
        s32 delta, newdelta;
 
-       timeval_usec_add(waketime, add_usec);
-
-       do_gettimeofday(&lasttime);
-       delta = timeval_usec_diff(lasttime, *waketime);
+       ktime_add_us(*waketime, add_usec);
+       delta = ktime_us_delta(ktime_get_real(), *waketime);
        if (delta > 2500) {
                msleep((delta - 1500) / 1000);
-               do_gettimeofday(&lasttime);
-               newdelta = timeval_usec_diff(lasttime, *waketime);
+               newdelta = ktime_us_delta(ktime_get_real(), *waketime);
                delta = (newdelta > delta) ? 0 : newdelta;
        }
        if (delta > 0)
@@ -2458,13 +2438,13 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
                         * include the initialization or start bit
                         */
                        unsigned long swcmd = ((unsigned long) parg) << 1;
-                       struct timeval nexttime;
-                       struct timeval tv[10];
+                       ktime_t nexttime;
+                       ktime_t tv[10];
                        int i;
                        u8 last = 1;
                        if (dvb_frontend_debug)
                                printk("%s switch command: 0x%04lx\n", 
__func__, swcmd);
-                       do_gettimeofday(&nexttime);
+                       nexttime = ktime_get_real();
                        if (dvb_frontend_debug)
                                tv[0] = nexttime;
                        /* before sending a command, initialize by sending
@@ -2475,7 +2455,7 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
 
                        for (i = 0; i < 9; i++) {
                                if (dvb_frontend_debug)
-                                       do_gettimeofday(&tv[i + 1]);
+                                       tv[i+1] = ktime_get_real();
                                if ((swcmd & 0x01) != last) {
                                        /* set voltage to (last ? 13V : 18V) */
                                        fe->ops.set_voltage(fe, (last) ? 
SEC_VOLTAGE_13 : SEC_VOLTAGE_18);
@@ -2489,7 +2469,8 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
                                printk("%s(%d): switch delay (should be 32k 
followed by all 8k\n",
                                        __func__, fe->dvb->num);
                                for (i = 1; i < 10; i++)
-                                       printk("%d: %d\n", i, 
timeval_usec_diff(tv[i-1] , tv[i]));
+                                       printk("%d: %d\n", i,
+                                       (int) ktime_us_delta(tv[i], tv[i-1]);
                        }
                        err = 0;
                        fepriv->state = FESTATE_DISEQC;
diff --git a/drivers/media/dvb-core/dvb_frontend.h 
b/drivers/media/dvb-core/dvb_frontend.h
index 816269e..5b64686 100644
--- a/drivers/media/dvb-core/dvb_frontend.h
+++ b/drivers/media/dvb-core/dvb_frontend.h
@@ -439,7 +439,6 @@ extern void dvb_frontend_reinitialise(struct dvb_frontend 
*fe);
 extern int dvb_frontend_suspend(struct dvb_frontend *fe);
 extern int dvb_frontend_resume(struct dvb_frontend *fe);
 
-extern void dvb_frontend_sleep_until(struct timeval *waketime, u32 add_usec);
-extern s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime);
+extern void dvb_frontend_sleep_until(ktime_t *waketime, u32 add_usec);
 
 #endif
diff --git a/drivers/media/dvb-frontends/stv0299.c 
b/drivers/media/dvb-frontends/stv0299.c
index b57ecf4..347c2bc 100644
--- a/drivers/media/dvb-frontends/stv0299.c
+++ b/drivers/media/dvb-frontends/stv0299.c
@@ -44,6 +44,7 @@
 
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/slab.h>
@@ -404,8 +405,8 @@ static int stv0299_send_legacy_dish_cmd (struct 
dvb_frontend* fe, unsigned long
        u8 lv_mask = 0x40;
        u8 last = 1;
        int i;
-       struct timeval nexttime;
-       struct timeval tv[10];
+       ktime_t nexttime;
+       ktime_t tv[10];
 
        reg0x08 = stv0299_readreg (state, 0x08);
        reg0x0c = stv0299_readreg (state, 0x0c);
@@ -418,7 +419,7 @@ static int stv0299_send_legacy_dish_cmd (struct 
dvb_frontend* fe, unsigned long
        if (debug_legacy_dish_switch)
                printk ("%s switch command: 0x%04lx\n",__func__, cmd);
 
-       do_gettimeofday (&nexttime);
+       nexttime = ktime_get_real();
        if (debug_legacy_dish_switch)
                tv[0] = nexttime;
        stv0299_writeregI (state, 0x0c, reg0x0c | 0x50); /* set LNB to 18V */
@@ -427,7 +428,7 @@ static int stv0299_send_legacy_dish_cmd (struct 
dvb_frontend* fe, unsigned long
 
        for (i=0; i<9; i++) {
                if (debug_legacy_dish_switch)
-                       do_gettimeofday (&tv[i+1]);
+                       tv[i+1] = ktime_get_real();
                if((cmd & 0x01) != last) {
                        /* set voltage to (last ? 13V : 18V) */
                        stv0299_writeregI (state, 0x0c, reg0x0c | (last ? 
lv_mask : 0x50));
@@ -443,7 +444,8 @@ static int stv0299_send_legacy_dish_cmd (struct 
dvb_frontend* fe, unsigned long
                printk ("%s(%d): switch delay (should be 32k followed by all 
8k\n",
                        __func__, fe->dvb->num);
                for (i = 1; i < 10; i++)
-                       printk ("%d: %d\n", i, timeval_usec_diff(tv[i-1] , 
tv[i]));
+                       printk("%d: %d\n", i,
+                              (int) ktime_us_delta(tv[i], tv[i-1]));
        }
 
        return 0;
-- 
2.2.0.rc0.207.ga3a616c

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