net: fec: reduce spin lock time in fec_ptp_adjfreq

move below calculate out of spin lock section
	diff = fep->cc.mult;
	diff *= ppb;
	diff = div_u64(diff, 1000000000ULL);

diff is local variable and not neccesary in spin lock

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index 5352140468ce..c40526c78c20 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -145,6 +145,7 @@ static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
         u64 diff;
         unsigned long flags;
         int neg_adj = 0;
+        u32 mult = FEC_CC_MULT;
 
         struct fec_enet_private *fep =
             container_of(ptp, struct fec_enet_private, ptp_caps);
@@ -154,6 +155,10 @@ static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
                 neg_adj = 1;
         }
 
+        diff = mult;
+        diff *= ppb;
+        diff = div_u64(diff, 1000000000ULL);
+
         spin_lock_irqsave(&fep->tmreg_lock, flags);
         /*
          * dummy read to set cycle_last in tc to now.
@@ -161,15 +166,8 @@ static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
          * timercounter_read.
          */
         timecounter_read(&fep->tc);
-        fep->cc.mult = FEC_CC_MULT;
-        diff = fep->cc.mult;
-        diff *= ppb;
-        diff = div_u64(diff, 1000000000ULL);
 
-        if (neg_adj)
-                fep->cc.mult -= diff;
-        else
-                fep->cc.mult += diff;
+        fep->cc.mult = neg_adj ? mult - diff : mult + diff;
 
         spin_unlock_irqrestore(&fep->tmreg_lock, flags);