netdev - Re: [PATCH v2 net-next 04/14] ptp: netc: add PTP_CLK_REQ

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aHkTkdFaYd8IOkpG@lizhi-Precision-Tower-5810>
Date: Thu, 17 Jul 2025 11:15:29 -0400
From: Frank Li <Frank.li@....com>
To: Wei Fang <wei.fang@....com>
Cc: "robh@...nel.org" <robh@...nel.org>,
	"krzk+dt@...nel.org" <krzk+dt@...nel.org>,
	"conor+dt@...nel.org" <conor+dt@...nel.org>,
	"richardcochran@...il.com" <richardcochran@...il.com>,
	Claudiu Manoil <claudiu.manoil@....com>,
	Vladimir Oltean <vladimir.oltean@....com>,
	Clark Wang <xiaoning.wang@....com>,
	"andrew+netdev@...n.ch" <andrew+netdev@...n.ch>,
	"davem@...emloft.net" <davem@...emloft.net>,
	"edumazet@...gle.com" <edumazet@...gle.com>,
	"kuba@...nel.org" <kuba@...nel.org>,
	"pabeni@...hat.com" <pabeni@...hat.com>,
	"vadim.fedorenko@...ux.dev" <vadim.fedorenko@...ux.dev>,
	"shawnguo@...nel.org" <shawnguo@...nel.org>,
	"s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
	"festevam@...il.com" <festevam@...il.com>,
	"F.S. Peng" <fushi.peng@....com>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"imx@...ts.linux.dev" <imx@...ts.linux.dev>,
	"kernel@...gutronix.de" <kernel@...gutronix.de>
Subject: Re: [PATCH v2 net-next 04/14] ptp: netc: add PTP_CLK_REQ_PPS support

On Thu, Jul 17, 2025 at 11:59:30AM +0000, Wei Fang wrote:
> > > +static u32 netc_timer_calculate_fiper_pw(struct netc_timer *priv,
> > > +					 u32 fiper)
> > > +{
> > > +	u64 divisor, pulse_width;
> > > +
> > > +	/* Set the FIPER pulse width to half FIPER interval by default.
> > > +	 * pulse_width = (fiper / 2) / TMR_GCLK_period,
> > > +	 * TMR_GCLK_period = NSEC_PER_SEC / TMR_GCLK_freq,
> > > +	 * TMR_GCLK_freq = (clk_freq / oclk_prsc) Hz,
> > > +	 * so pulse_width = fiper * clk_freq / (2 * NSEC_PER_SEC * oclk_prsc).
> > > +	 */
> > > +	divisor = mul_u32_u32(2000000000U, priv->oclk_prsc);
> >
> > is it 2*PSEC_PER_SEC ?
> >
>
> No, it is 2 * NSEC_PER_SEC, NSEC_PER_SEC is 1000000000.

Use 2 * NSEC_PER_SEC, instead of hardcode number.

Frank

>