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authorFrank Li <Frank.Li@freescale.com>2012-11-06 20:14:49 +0000
committerDavid S. Miller <davem@davemloft.net>2012-11-07 18:52:12 -0500
commit7da716aee2532399e213a14f656d304098f67a11 (patch)
tree7d294e94fc51a1b7e7ab1d9f7822d50e74670f6d
parent0f2f7a40f9ae91b9e837c3cd2cacd7f46c168eb1 (diff)
downloadlinux-7da716aee2532399e213a14f656d304098f67a11.tar.bz2
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>
-rw-r--r--drivers/net/ethernet/freescale/fec_ptp.c14
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);