[PATCH 0/6] driver/net/irda: Use ktime_t instead of timeval

[PATCH 0/6] driver/net/irda: Use ktime_t instead of timeval

[Chunyan Zhang]

This patch-set removed all uses of timeval and used ktime_t instead if
needed, since 32-bit time types will break in the year 2038.

This patch-set also used the ktime_xxx functions accordingly.
e.g.
* Used ktime_get to get the current time instead of do_gettimeofday.
* And, used ktime_us_delta to get the elapsed time directly.

Chunyan Zhang (6):
  driver/net/irda: Removed all unused timeval variables
  driver/net/irda: Replace timeval with ktime_t in ali-ircc
  driver/net/irda: Replace timeval with ktime_t in irda-usb
  driver/net/irda: Replace timeval with ktime_t in nsc-ircc
  driver/net/irda: Replace timeval with ktime_t in stir4200
  driver/net/irda: Replace timeval with ktime_t in vlsi_ir

 drivers/net/irda/ali-ircc.c    |   12 ++++------
 drivers/net/irda/ali-ircc.h    |    6 ++---
 drivers/net/irda/au1k_ir.c     |    3 ---
 drivers/net/irda/irda-usb.c    |   11 +++------
 drivers/net/irda/irda-usb.h    |    6 ++---
 drivers/net/irda/kingsun-sir.c |    3 ---
 drivers/net/irda/ks959-sir.c   |    3 ---
 drivers/net/irda/mcs7780.c     |    2 --
 drivers/net/irda/mcs7780.h     |    1 -
 drivers/net/irda/nsc-ircc.c    |    8 +++----
 drivers/net/irda/nsc-ircc.h    |    6 ++---
 drivers/net/irda/stir4200.c    |   18 +++++++-------
 drivers/net/irda/via-ircc.h    |    4 ----
 drivers/net/irda/vlsi_ir.c     |   51 ++++++++++++++--------------------------
 drivers/net/irda/vlsi_ir.h     |    2 +-
 15 files changed, 46 insertions(+), 90 deletions(-)

-- 
1.7.9.5

[PATCH 1/6] driver/net/irda: Removed all unused timeval variables

[Chunyan Zhang]

In the file au1k_ir.c & via-ircc.h, there were two unused
definitions of the timeval type members, so I removed them
entirely in this patch.

In other three files, the same problem is the rx_time
member is only ever written, never read, so removed it
entirely.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
---
 drivers/net/irda/au1k_ir.c     |    3 ---
 drivers/net/irda/kingsun-sir.c |    3 ---
 drivers/net/irda/ks959-sir.c   |    3 ---
 drivers/net/irda/mcs7780.c     |    2 --
 drivers/net/irda/mcs7780.h     |    1 -
 drivers/net/irda/via-ircc.h    |    4 ----
 6 files changed, 16 deletions(-)

diff --git a/drivers/net/irda/au1k_ir.c b/drivers/net/irda/au1k_ir.c
index e151205..44e4f38 100644
--- a/drivers/net/irda/au1k_ir.c
+++ b/drivers/net/irda/au1k_ir.c
@@ -24,7 +24,6 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
-#include <linux/time.h>
 #include <linux/types.h>
 #include <linux/ioport.h>
 
@@ -163,8 +162,6 @@ struct au1k_private {
 	iobuff_t rx_buff;
 
 	struct net_device *netdev;
-	struct timeval stamp;
-	struct timeval now;
 	struct qos_info qos;
 	struct irlap_cb *irlap;
 
diff --git a/drivers/net/irda/kingsun-sir.c b/drivers/net/irda/kingsun-sir.c
index e638893..fb5d162 100644
--- a/drivers/net/irda/kingsun-sir.c
+++ b/drivers/net/irda/kingsun-sir.c
@@ -114,7 +114,6 @@ struct kingsun_cb {
 					   (usually 8) */
 
 	iobuff_t  	  rx_buff;	/* receive unwrap state machine */
-	struct timeval	  rx_time;
 	spinlock_t lock;
 	int receiving;
 
@@ -235,7 +234,6 @@ static void kingsun_rcv_irq(struct urb *urb)
 						  &kingsun->netdev->stats,
 						  &kingsun->rx_buff, bytes[i]);
 			}
-			do_gettimeofday(&kingsun->rx_time);
 			kingsun->receiving =
 				(kingsun->rx_buff.state != OUTSIDE_FRAME)
 				? 1 : 0;
@@ -273,7 +271,6 @@ static int kingsun_net_open(struct net_device *netdev)
 
 	skb_reserve(kingsun->rx_buff.skb, 1);
 	kingsun->rx_buff.head = kingsun->rx_buff.skb->data;
-	do_gettimeofday(&kingsun->rx_time);
 
 	kingsun->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!kingsun->rx_urb)
diff --git a/drivers/net/irda/ks959-sir.c b/drivers/net/irda/ks959-sir.c
index e6b3804..8e6e0ed 100644
--- a/drivers/net/irda/ks959-sir.c
+++ b/drivers/net/irda/ks959-sir.c
@@ -187,7 +187,6 @@ struct ks959_cb {
 	__u8 *rx_buf;
 	__u8 rx_variable_xormask;
 	iobuff_t rx_unwrap_buff;
-	struct timeval rx_time;
 
 	struct usb_ctrlrequest *speed_setuprequest;
 	struct urb *speed_urb;
@@ -476,7 +475,6 @@ static void ks959_rcv_irq(struct urb *urb)
 						  bytes[i]);
 			}
 		}
-		do_gettimeofday(&kingsun->rx_time);
 		kingsun->receiving =
 		    (kingsun->rx_unwrap_buff.state != OUTSIDE_FRAME) ? 1 : 0;
 	}
@@ -514,7 +512,6 @@ static int ks959_net_open(struct net_device *netdev)
 
 	skb_reserve(kingsun->rx_unwrap_buff.skb, 1);
 	kingsun->rx_unwrap_buff.head = kingsun->rx_unwrap_buff.skb->data;
-	do_gettimeofday(&kingsun->rx_time);
 
 	kingsun->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!kingsun->rx_urb)
diff --git a/drivers/net/irda/mcs7780.c b/drivers/net/irda/mcs7780.c
index e4d678f..bca6a1e 100644
--- a/drivers/net/irda/mcs7780.c
+++ b/drivers/net/irda/mcs7780.c
@@ -722,7 +722,6 @@ static int mcs_net_open(struct net_device *netdev)
 
 	skb_reserve(mcs->rx_buff.skb, 1);
 	mcs->rx_buff.head = mcs->rx_buff.skb->data;
-	do_gettimeofday(&mcs->rx_time);
 
 	/*
 	 * Now that everything should be initialized properly,
@@ -799,7 +798,6 @@ static void mcs_receive_irq(struct urb *urb)
 			mcs_unwrap_fir(mcs, urb->transfer_buffer,
 				urb->actual_length);
 		}
-		do_gettimeofday(&mcs->rx_time);
 	}
 
 	ret = usb_submit_urb(urb, GFP_ATOMIC);
diff --git a/drivers/net/irda/mcs7780.h b/drivers/net/irda/mcs7780.h
index b10689b..a6e8f7d 100644
--- a/drivers/net/irda/mcs7780.h
+++ b/drivers/net/irda/mcs7780.h
@@ -116,7 +116,6 @@ struct mcs_cb {
 	__u8 *fifo_status;
 
 	iobuff_t rx_buff;	/* receive unwrap state machine */
-	struct timeval rx_time;
 	spinlock_t lock;
 	int receiving;
 
diff --git a/drivers/net/irda/via-ircc.h b/drivers/net/irda/via-ircc.h
index 7ce820e..ac15255 100644
--- a/drivers/net/irda/via-ircc.h
+++ b/drivers/net/irda/via-ircc.h
@@ -29,7 +29,6 @@ this program; if not, see <http://www.gnu.org/licenses/>.
  ********************************************************************/
 #ifndef via_IRCC_H
 #define via_IRCC_H
-#include <linux/time.h>
 #include <linux/spinlock.h>
 #include <linux/pm.h>
 #include <linux/types.h>
@@ -106,9 +105,6 @@ struct via_ircc_cb {
 
 	__u8 ier;		/* Interrupt enable register */
 
-	struct timeval stamp;
-	struct timeval now;
-
 	spinlock_t lock;	/* For serializing operations */
 
 	__u32 flags;		/* Interface flags */
-- 
1.7.9.5

[PATCH 2/6] driver/net/irda: Replace timeval with ktime_t in ali-ircc

[Chunyan Zhang]

This patch changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t), since 32-bit time types will break in the year 2038.
So, I use ktime_t instead of all uses of timeval.

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 use 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@linaro.org>
---
 drivers/net/irda/ali-ircc.c |   12 ++++--------
 drivers/net/irda/ali-ircc.h |    6 +++---
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/net/irda/ali-ircc.c b/drivers/net/irda/ali-ircc.c
index 58f98f4..ab041a4 100644
--- a/drivers/net/irda/ali-ircc.c
+++ b/drivers/net/irda/ali-ircc.c
@@ -1462,17 +1462,13 @@ static netdev_tx_t ali_ircc_fir_hard_xmit(struct sk_buff *skb,
 		if (mtt) 
 		{
 			/* Check how much time we have used already */
-			do_gettimeofday(&self->now);
-			
-			diff = self->now.tv_usec - self->stamp.tv_usec;
+			self->now = ktime_get();
+			diff = ktime_us_delta(self->now, self->stamp);
 			/* self->stamp is set from ali_ircc_dma_receive_complete() */
 							
 			pr_debug("%s(), ******* diff = %d *******\n",
 				 __func__, diff);
-			
-			if (diff < 0) 
-				diff += 1000000;
-			
+
 			/* Check if the mtt is larger than the time we have
 			 * already used by all the protocol processing
 			 */
@@ -1884,7 +1880,7 @@ static int  ali_ircc_dma_receive_complete(struct ali_ircc_cb *self)
 			 * 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();
 
 			skb = dev_alloc_skb(len+1);
 			if (skb == NULL)  
diff --git a/drivers/net/irda/ali-ircc.h b/drivers/net/irda/ali-ircc.h
index 0c8edb4..164ee42 100644
--- a/drivers/net/irda/ali-ircc.h
+++ b/drivers/net/irda/ali-ircc.h
@@ -22,7 +22,7 @@
 #ifndef ALI_IRCC_H
 #define ALI_IRCC_H
 
-#include <linux/time.h>
+#include <linux/ktime.h>
 
 #include <linux/spinlock.h>
 #include <linux/pm.h>
@@ -209,8 +209,8 @@ struct ali_ircc_cb {
 	
 	unsigned char rcvFramesOverflow;
 		
-	struct timeval stamp;
-	struct timeval now;
+	ktime_t stamp;
+	ktime_t now;
 
 	spinlock_t lock;           /* For serializing operations */
 	
-- 
1.7.9.5

[PATCH 3/6] driver/net/irda: Replace timeval with ktime_t in irda-usb

[Chunyan Zhang]

This patch changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t), since 32-bit time types will break in the year 2038.
So, I use ktime_t instead of all uses of timeval.

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 use 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@linaro.org>
---
 drivers/net/irda/irda-usb.c |   11 +++--------
 drivers/net/irda/irda-usb.h |    6 +++---
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/net/irda/irda-usb.c b/drivers/net/irda/irda-usb.c
index 48b2f9a..be86840 100644
--- a/drivers/net/irda/irda-usb.c
+++ b/drivers/net/irda/irda-usb.c
@@ -495,18 +495,13 @@ 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;
+			self->now = ktime_get();
+			diff = ktime_us_delta(self->now, 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 +864,7 @@ 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..8093216 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 +157,8 @@ struct irda_usb_cb {
 	char *speed_buff;		/* Buffer for speed changes */
 	char *tx_buff;
 
-	struct timeval stamp;
-	struct timeval now;
+	ktime_t stamp;
+	ktime_t now;
 
 	spinlock_t lock;		/* For serializing Tx operations */
 
-- 
1.7.9.5

[PATCH 4/6] driver/net/irda: Replace timeval with ktime_t in nsc-ircc

[Chunyan Zhang]

This patch changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t), since 32-bit time types will break in the year 2038.
So, I use ktime_t instead of all uses of timeval.

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 use 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@linaro.org>
---
 drivers/net/irda/nsc-ircc.c |    8 +++-----
 drivers/net/irda/nsc-ircc.h |    6 +++---
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/net/irda/nsc-ircc.c b/drivers/net/irda/nsc-ircc.c
index e7317b1..cabb82e 100644
--- a/drivers/net/irda/nsc-ircc.c
+++ b/drivers/net/irda/nsc-ircc.c
@@ -1501,10 +1501,8 @@ static netdev_tx_t nsc_ircc_hard_xmit_fir(struct sk_buff *skb,
 		mtt = irda_get_mtt(skb);
 		if (mtt) {
 			/* Check how much time we have used already */
-			do_gettimeofday(&self->now);
-			diff = self->now.tv_usec - self->stamp.tv_usec;
-			if (diff < 0) 
-				diff += 1000000;
+			self->now = ktime_get();
+			diff = ktime_us_delta(self->now, self->stamp);
 			
 			/* Check if the mtt is larger than the time we have
 			 * already used by all the protocol processing
@@ -1867,7 +1865,7 @@ static int nsc_ircc_dma_receive_complete(struct nsc_ircc_cb *self, int iobase)
 			 * 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();
 
 			skb = dev_alloc_skb(len+1);
 			if (skb == NULL)  {
diff --git a/drivers/net/irda/nsc-ircc.h b/drivers/net/irda/nsc-ircc.h
index 32fa582..dd2185a 100644
--- a/drivers/net/irda/nsc-ircc.h
+++ b/drivers/net/irda/nsc-ircc.h
@@ -28,7 +28,7 @@
 #ifndef NSC_IRCC_H
 #define NSC_IRCC_H
 
-#include <linux/time.h>
+#include <linux/ktime.h>
 
 #include <linux/spinlock.h>
 #include <linux/pm.h>
@@ -263,8 +263,8 @@ struct nsc_ircc_cb {
 
 	__u8 ier;                  /* Interrupt enable register */
 
-	struct timeval stamp;
-	struct timeval now;
+	ktime_t stamp;
+	ktime_t	now;
 
 	spinlock_t lock;           /* For serializing operations */
 	
-- 
1.7.9.5

[PATCH 5/6] driver/net/irda: Replace timeval with ktime_t in stir4200

[Chunyan Zhang]

This patch changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t), since 32-bit time types will break in the year 2038.
So, I use ktime_t instead of all uses of timeval.

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 use ktime_us_delta to get the elapsed time of microsecond.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
---
 drivers/net/irda/stir4200.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/irda/stir4200.c b/drivers/net/irda/stir4200.c
index dd1bd10..008e12d 100644
--- a/drivers/net/irda/stir4200.c
+++ b/drivers/net/irda/stir4200.c
@@ -40,6 +40,7 @@
 #include <linux/moduleparam.h>
 
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/types.h>
 #include <linux/time.h>
 #include <linux/skbuff.h>
@@ -174,7 +175,7 @@ struct stir_cb {
 	__u8		  *fifo_status;
 
 	iobuff_t  	  rx_buff;	/* receive unwrap state machine */
-	struct timeval	  rx_time;
+	ktime_t		rx_time;
 	int		  receiving;
 	struct urb	 *rx_urb;
 };
@@ -650,15 +651,14 @@ static int fifo_txwait(struct stir_cb *stir, int space)
 static void turnaround_delay(const struct stir_cb *stir, long us)
 {
 	long ticks;
-	struct timeval now;
+	ktime_t now;
 
 	if (us <= 0)
 		return;
 
-	do_gettimeofday(&now);
-	if (now.tv_sec - stir->rx_time.tv_sec > 0)
-		us -= USEC_PER_SEC;
-	us -= now.tv_usec - stir->rx_time.tv_usec;
+	now = ktime_get();
+	us -= ktime_us_delta(now, stir->rx_time);
+
 	if (us < 10)
 		return;
 
@@ -823,8 +823,8 @@ static void stir_rcv_irq(struct urb *urb)
 		pr_debug("receive %d\n", urb->actual_length);
 		unwrap_chars(stir, urb->transfer_buffer,
 			     urb->actual_length);
-		
-		do_gettimeofday(&stir->rx_time);
+
+		stir->rx_time = ktime_get();
 	}
 
 	/* kernel thread is stopping receiver don't resubmit */
@@ -876,7 +876,7 @@ static int stir_net_open(struct net_device *netdev)
 
 	skb_reserve(stir->rx_buff.skb, 1);
 	stir->rx_buff.head = stir->rx_buff.skb->data;
-	do_gettimeofday(&stir->rx_time);
+	stir->rx_time = ktime_get();
 
 	stir->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!stir->rx_urb) 
-- 
1.7.9.5

[PATCH 6/6] driver/net/irda: Replace timeval with ktime_t in vlsi_ir

[Chunyan Zhang]

This patch changes the 32-bit time type (timeval) to the 64-bit one
(ktime_t), since 32-bit time types will break in the year 2038.
So, I use ktime_t instead of all uses of timeval.

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 of microsecond,
and uses div_s64_rem to get what seconds & microseconds time elapsed
for printing.

This patch also changes the code of function 'vlsi_hard_start_xmit' to
do the same things as the others drivers, that is passing the remaining
time into udelay() instead of looping until enough time has passed.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
---
 drivers/net/irda/vlsi_ir.c |   51 +++++++++++++++-----------------------------
 drivers/net/irda/vlsi_ir.h |    2 +-
 2 files changed, 18 insertions(+), 35 deletions(-)

diff --git a/drivers/net/irda/vlsi_ir.c b/drivers/net/irda/vlsi_ir.c
index ac39d9f..a60a73d 100644
--- a/drivers/net/irda/vlsi_ir.c
+++ b/drivers/net/irda/vlsi_ir.c
@@ -33,6 +33,7 @@ MODULE_LICENSE("GPL");
 /********************************************************/
 
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/pci.h>
@@ -40,9 +41,9 @@ MODULE_LICENSE("GPL");
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
 #include <linux/delay.h>
-#include <linux/time.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/math64.h>
 #include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include <asm/byteorder.h>
@@ -180,8 +181,8 @@ static void vlsi_proc_ndev(struct seq_file *seq, struct net_device *ndev)
 	vlsi_irda_dev_t *idev = netdev_priv(ndev);
 	u8 byte;
 	u16 word;
-	unsigned delta1, delta2;
-	struct timeval now;
+	ktime_t now;
+	s32 sec, usec;
 	unsigned iobase = ndev->base_addr;
 
 	seq_printf(seq, "\n%s link state: %s / %s / %s / %s\n", ndev->name,
@@ -277,17 +278,10 @@ static void vlsi_proc_ndev(struct seq_file *seq, struct net_device *ndev)
 	seq_printf(seq, "\nsw-state:\n");
 	seq_printf(seq, "IrPHY setup: %d baud - %s encoding\n", idev->baud, 
 		(idev->mode==IFF_SIR)?"SIR":((idev->mode==IFF_MIR)?"MIR":"FIR"));
-	do_gettimeofday(&now);
-	if (now.tv_usec >= idev->last_rx.tv_usec) {
-		delta2 = now.tv_usec - idev->last_rx.tv_usec;
-		delta1 = 0;
-	}
-	else {
-		delta2 = 1000000 + now.tv_usec - idev->last_rx.tv_usec;
-		delta1 = 1;
-	}
-	seq_printf(seq, "last rx: %lu.%06u sec\n",
-		now.tv_sec - idev->last_rx.tv_sec - delta1, delta2);	
+	now = ktime_get();
+	sec = div_s64_rem(ktime_us_delta(now, idev->last_rx),
+			  USEC_PER_SEC, &usec);
+	seq_printf(seq, "last rx: %ul.%06u sec\n", sec, usec);
 
 	seq_printf(seq, "RX: packets=%lu / bytes=%lu / errors=%lu / dropped=%lu",
 		ndev->stats.rx_packets, ndev->stats.rx_bytes, ndev->stats.rx_errors,
@@ -661,7 +655,7 @@ static void vlsi_rx_interrupt(struct net_device *ndev)
 		}
 	}
 
-	do_gettimeofday(&idev->last_rx); /* remember "now" for later mtt delay */
+	idev->last_rx = ktime_get(); /* remember "now" for later mtt delay */
 
 	vlsi_fill_rx(r);
 
@@ -858,9 +852,9 @@ static netdev_tx_t vlsi_hard_start_xmit(struct sk_buff *skb,
 	unsigned iobase = ndev->base_addr;
 	u8 status;
 	u16 config;
-	int mtt;
+	int mtt, diff;
 	int len, speed;
-	struct timeval  now, ready;
+	ktime_t  now;
 	char *msg = NULL;
 
 	speed = irda_get_next_speed(skb);
@@ -940,21 +934,10 @@ static netdev_tx_t vlsi_hard_start_xmit(struct sk_buff *skb,
 	spin_unlock_irqrestore(&idev->lock, flags);
 
 	if ((mtt = irda_get_mtt(skb)) > 0) {
-	
-		ready.tv_usec = idev->last_rx.tv_usec + mtt;
-		ready.tv_sec = idev->last_rx.tv_sec;
-		if (ready.tv_usec >= 1000000) {
-			ready.tv_usec -= 1000000;
-			ready.tv_sec++;		/* IrLAP 1.1: mtt always < 1 sec */
-		}
-		for(;;) {
-			do_gettimeofday(&now);
-			if (now.tv_sec > ready.tv_sec ||
-			    (now.tv_sec==ready.tv_sec && now.tv_usec>=ready.tv_usec))
-			    	break;
-			udelay(100);
-			/* must not sleep here - called under netif_tx_lock! */
-		}
+		now = ktime_get();
+		diff = ktime_us_delta(now, idev->last_rx);
+		if (mtt > diff)
+			udelay(mtt - diff);
 	}
 
 	/* tx buffer already owned by CPU due to pci_dma_sync_single_for_cpu()
@@ -1333,7 +1316,7 @@ static int vlsi_start_hw(vlsi_irda_dev_t *idev)
 
 	vlsi_fill_rx(idev->rx_ring);
 
-	do_gettimeofday(&idev->last_rx);	/* first mtt may start from now on */
+	idev->last_rx = ktime_get();	/* first mtt may start from now on */
 
 	outw(0, iobase+VLSI_PIO_PROMPT);	/* kick hw state machine */
 
@@ -1520,7 +1503,7 @@ static int vlsi_open(struct net_device *ndev)
 	if (!idev->irlap)
 		goto errout_free_ring;
 
-	do_gettimeofday(&idev->last_rx);  /* first mtt may start from now on */
+	idev->last_rx = ktime_get();  /* first mtt may start from now on */
 
 	idev->new_baud = 9600;		/* start with IrPHY using 9600(SIR) mode */
 
diff --git a/drivers/net/irda/vlsi_ir.h b/drivers/net/irda/vlsi_ir.h
index f9119c6..f9db2ce 100644
--- a/drivers/net/irda/vlsi_ir.h
+++ b/drivers/net/irda/vlsi_ir.h
@@ -723,7 +723,7 @@ typedef struct vlsi_irda_dev {
 	void			*virtaddr;
 	struct vlsi_ring	*tx_ring, *rx_ring;
 
-	struct timeval		last_rx;
+	ktime_t			last_rx;
 
 	spinlock_t		lock;
 	struct mutex		mtx;
-- 
1.7.9.5

Re: [PATCH 6/6] driver/net/irda: Replace timeval with ktime_t in vlsi_ir

[Arnd Bergmann]

On Wednesday 07 January 2015 11:39:38 Chunyan Zhang wrote:
> This patch changes the 32-bit time type (timeval) to the 64-bit one
> (ktime_t), since 32-bit time types will break in the year 2038.
> So, I use ktime_t instead of all uses of timeval.
> 
> 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 of microsecond,
> and uses div_s64_rem to get what seconds & microseconds time elapsed
> for printing.
> 
> This patch also changes the code of function 'vlsi_hard_start_xmit' to
> do the same things as the others drivers, that is passing the remaining
> time into udelay() instead of looping until enough time has passed.
> 
> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>

All six patches look correct to me now, nice work!

I have a few very minor comments still, some of which apply to the
other patches as well:

* Your patch changelog starts each paragraph with 'This patch', which is
  correct but is a little strange to read. You could start the first paragraph
  explaining what the driver currently does and why we want to change it,
  like "The vlsi ir driver uses 'timeval', which we try to remove in the
  kernel because all 32-bit time types will break in the year 2038".

* It would also be good to explain that none of these drivers are actually
  broken regarding y2038 at the moment and that the change is only done to
  remove the need for auditing this fact again.

> @@ -180,8 +181,8 @@ static void vlsi_proc_ndev(struct seq_file *seq, struct net_device *ndev)
>  	vlsi_irda_dev_t *idev = netdev_priv(ndev);
>  	u8 byte;
>  	u16 word;
> -	unsigned delta1, delta2;
> -	struct timeval now;
> +	ktime_t now;
> +	s32 sec, usec;
>  	unsigned iobase = ndev->base_addr;

* you now have a local variable that is only used to be passed into ktime_us_delta.
  While there is no difference to the compiler, I would probably shorten this
  and avoid the local variable by passing the result of ktime_get() directly
  into ktime_us_delta().
  For the drivers that store the 'now' variable in a data structure, doing the
  same change shrinks the driver specific data structure, which is an added
  benefit.

> -		for(;;) {
> -			do_gettimeofday(&now);
> -			if (now.tv_sec > ready.tv_sec ||
> -			    (now.tv_sec==ready.tv_sec && now.tv_usec>=ready.tv_usec))
> -			    	break;
> -			udelay(100);
> -			/* must not sleep here - called under netif_tx_lock! */
> -		}
> +		now = ktime_get();
> +		diff = ktime_us_delta(now, idev->last_rx);
> +		if (mtt > diff)
> +			udelay(mtt - diff);
>  	}

The change looks good, but you remove a useful comment about sleeping inside of
netif_tx_lock. I would not bother adding the same comment to the other drivers,
but it still applies to the udelay call here so I would move it there.
Note that generally we try hard to avoid the use of long 'udelay' calls, but
I wouldn't expect you to change the drivers for this.

When you submit the next version and you have addressed my last comments,
please add

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

	Arnd