* [PATCH 2/2] net: fec: reduce spin lock time in fec_ptp_adjfreq
@ 2012-11-07 6:14 Frank Li
2012-11-07 8:33 ` Richard Cochran
2012-11-07 23:53 ` David Miller
0 siblings, 2 replies; 3+ messages in thread
From: Frank Li @ 2012-11-07 6:14 UTC (permalink / raw)
To: lznuaa, richardcochran, shawn.guo, linux-arm-kernel, netdev,
davem, bhutchings
Cc: Frank Li
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>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2] net: fec: reduce spin lock time in fec_ptp_adjfreq
2012-11-07 6:14 [PATCH 2/2] net: fec: reduce spin lock time in fec_ptp_adjfreq Frank Li
@ 2012-11-07 8:33 ` Richard Cochran
2012-11-07 23:53 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: Richard Cochran @ 2012-11-07 8:33 UTC (permalink / raw)
To: Frank Li; +Cc: lznuaa, shawn.guo, linux-arm-kernel, netdev, davem, bhutchings
On Wed, Nov 07, 2012 at 02:14:49PM +0800, Frank Li wrote:
> 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>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2] net: fec: reduce spin lock time in fec_ptp_adjfreq
2012-11-07 6:14 [PATCH 2/2] net: fec: reduce spin lock time in fec_ptp_adjfreq Frank Li
2012-11-07 8:33 ` Richard Cochran
@ 2012-11-07 23:53 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2012-11-07 23:53 UTC (permalink / raw)
To: Frank.Li
Cc: lznuaa, richardcochran, shawn.guo, linux-arm-kernel, netdev,
bhutchings
From: Frank Li <Frank.Li@freescale.com>
Date: Wed, 7 Nov 2012 14:14:49 +0800
> 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>
Also applied, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
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