irda: vlsi_ir: Replace timeval with ktime_t

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.

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 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>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 14 insertions, 34 deletions

diff --git a/drivers/net/irda/vlsi_ir.c b/drivers/net/irda/vlsi_ir.c
index ac39d9f33d5f..a0849f49bbec 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 +181,7 @@ 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;
+        s32 sec, usec;
         unsigned iobase = ndev->base_addr;
 
         seq_printf(seq, "\n%s link state: %s / %s / %s / %s\n", ndev->name,
@@ -277,17 +277,9 @@ 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);    
+        sec = div_s64_rem(ktime_us_delta(ktime_get(), 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 +653,7 @@ 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 +850,8 @@ 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;
         char *msg = NULL;
 
         speed = irda_get_next_speed(skb);
@@ -940,21 +931,10 @@ 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);
+                diff = ktime_us_delta(ktime_get(), idev->last_rx);
+                if (mtt > diff)
+                        udelay(mtt - diff);
                         /* must not sleep here - called under netif_tx_lock! */
-                }
         }
 
         /* tx buffer already owned by CPU due to pci_dma_sync_single_for_cpu()
@@ -1333,7 +1313,7 @@ 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 +1500,7 @@ 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 f9119c6d2a09..f9db2ce4c5c6 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;