[PATCH 2/2] net: fec: reduce spin lock time in fec_ptp_adjfreq
From: Frank Li <hidden>
Date: 2012-11-07 06:57:35
Subsystem:
freescale imx / mxc fec driver, networking drivers, the rest · Maintainers:
Wei Fang, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- drivers/net/ethernet/freescale/fec_ptp.c | 14 ++++++-------- 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 5352140..c40526c 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);
--
1.7.1