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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>
hifive-unleashed-5.1
Frank Li 2012-11-06 20:14:49 +00:00 committed by David S. Miller
parent 0f2f7a40f9
commit 7da716aee2
1 changed files with 6 additions and 8 deletions
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14
drivers/net/ethernet/freescale/fec_ptp.c
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@ -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);