[PATCH v2 3/6] irda: irda-usb: Replace timeval with ktime_t

From: Chunyan Zhang
Date: Wed Jan 07 2015 - 23:03:49 EST


The irda usb driver uses 'timeval', which we try to remove in the kernel
because all 32-bit time types will break in the year 2038.

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 uses ktime_us_delta to get the elapsed time, and in this
way it no longer needs to check for the overflow, because
ktime_us_delta returns time difference of microsecond.

Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/irda/irda-usb.c | 10 ++--------
drivers/net/irda/irda-usb.h | 5 ++---
2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/net/irda/irda-usb.c b/drivers/net/irda/irda-usb.c
index 48b2f9a..f6c9163 100644
--- a/drivers/net/irda/irda-usb.c
+++ b/drivers/net/irda/irda-usb.c
@@ -495,18 +495,12 @@ static netdev_tx_t irda_usb_hard_xmit(struct sk_buff *skb,
mtt = irda_get_mtt(skb);
if (mtt) {
int diff;
- do_gettimeofday(&self->now);
- diff = self->now.tv_usec - self->stamp.tv_usec;
+ diff = ktime_us_delta(ktime_get(), self->stamp);
#ifdef IU_USB_MIN_RTT
/* Factor in USB delays -> Get rid of udelay() that
* would be lost in the noise - Jean II */
diff += IU_USB_MIN_RTT;
#endif /* IU_USB_MIN_RTT */
- /* If the usec counter did wraparound, the diff will
- * go negative (tv_usec is a long), so we need to
- * correct it by one second. Jean II */
- if (diff < 0)
- diff += 1000000;

/* Check if the mtt is larger than the time we have
* already used by all the protocol processing
@@ -869,7 +863,7 @@ static void irda_usb_receive(struct urb *urb)
* reduce the min turn time a bit since we will know
* how much time we have used for protocol processing
*/
- do_gettimeofday(&self->stamp);
+ self->stamp = ktime_get();

/* Check if we need to copy the data to a new skb or not.
* For most frames, we use ZeroCopy and pass the already
diff --git a/drivers/net/irda/irda-usb.h b/drivers/net/irda/irda-usb.h
index 58ddb52..8ac389f 100644
--- a/drivers/net/irda/irda-usb.h
+++ b/drivers/net/irda/irda-usb.h
@@ -29,7 +29,7 @@
*
*****************************************************************************/

-#include <linux/time.h>
+#include <linux/ktime.h>

#include <net/irda/irda.h>
#include <net/irda/irda_device.h> /* struct irlap_cb */
@@ -157,8 +157,7 @@ struct irda_usb_cb {
char *speed_buff; /* Buffer for speed changes */
char *tx_buff;

- struct timeval stamp;
- struct timeval now;
+ ktime_t stamp;

spinlock_t lock; /* For serializing Tx operations */

--
1.7.9.5

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