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[media] staging: media: lirc: Replace timeval with ktime_t in lirc_sasem.c

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'struct timeval presstime' and 'struct timeval tv' is used to
calculate the time since the last button press.

32-bit systems using 'struct timeval' will break in the year 2038,
so we have to replace that code with more appropriate types.
This patch changes the media: lirc driver to use ktime_t.

ktime_get() is  better than using do_gettimeofday(), because it uses
the monotonic clock. ktime_sub() are used to subtract two ktime
variables. 'ms' is only used to check how much time has passed by comparing
to 250. So instead of using expensive ktime_to_ms() call, it has been
changed to hold nanoseconds by using ktime_to_ns().

Build tested it. Tested with sparse too.

Signed-off-by: Tapasweni Pathak <tapaswenipathak@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Arnd Bergmann 2015-11-25 13:12:53 -02:00 • committed by Mauro Carvalho Chehab
parent 8459503295
commit f07c73fea2
1 changed files with 9 additions and 11 deletions

20
drivers/staging/media/lirc/lirc_sasem.c
View file

@ -42,6 +42,7 @@
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/ktime.h>
#include <media/lirc.h>
#include <media/lirc_dev.h>
@ -111,7 +112,7 @@ struct sasem_context {
} tx;
/* for dealing with repeat codes (wish there was a toggle bit!) */
struct timeval presstime;
ktime_t presstime;
char lastcode[8];
int codesaved;
};
@ -566,8 +567,8 @@ static void incoming_packet(struct sasem_context *context,
{
int len = urb->actual_length;
unsigned char *buf = urb->transfer_buffer;
long ms;
struct timeval tv;
u64 ns;
ktime_t kt;
if (len != 8) {
dev_warn(&context->dev->dev,
@ -584,9 +585,8 @@ static void incoming_packet(struct sasem_context *context,
*/
/* get the time since the last button press */
do_gettimeofday(&tv);
ms = (tv.tv_sec - context->presstime.tv_sec) * 1000 +
(tv.tv_usec - context->presstime.tv_usec) / 1000;
kt = ktime_get();
ns = ktime_to_ns(ktime_sub(kt, context->presstime));
if (memcmp(buf, "\x08\0\0\0\0\0\0\0", 8) == 0) {
/*
@ -600,10 +600,9 @@ static void incoming_packet(struct sasem_context *context,
* in that time and then get a false repeat of the previous
* press but it is long enough for a genuine repeat
*/
if ((ms < 250) && (context->codesaved != 0)) {
if ((ns < 250 * NSEC_PER_MSEC) && (context->codesaved != 0)) {
memcpy(buf, &context->lastcode, 8);
context->presstime.tv_sec = tv.tv_sec;
context->presstime.tv_usec = tv.tv_usec;
context->presstime = kt;
}
} else {
/* save the current valid code for repeats */
@ -613,8 +612,7 @@ static void incoming_packet(struct sasem_context *context,
* just for safety reasons
*/
context->codesaved = 1;
context->presstime.tv_sec = tv.tv_sec;
context->presstime.tv_usec = tv.tv_usec;
context->presstime = kt;
}
lirc_buffer_write(context->driver->rbuf, buf);