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Message-ID: <9e47339105060818383e2311f@mail.gmail.com>
Date: Wed, 8 Jun 2005 21:38:04 -0400
From: Jon Smirl <jonsmirl@gmail.com>
Reply-To: Jon Smirl <jonsmirl@gmail.com>
To: Lee Revell <rlrevell@joe-job.com>
Subject: Re: Dell BIOS and HPET timer support
Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>,
       lkml <linux-kernel@vger.kernel.org>, Bob Picco <Robert.Picco@hp.com>
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On 6/8/05, Lee Revell <rlrevell@joe-job.com> wrote:
> Check the source, it's self-explanatory.  See hpet_alloc().

What is going on with do_div()? 
0x0429b17f /100000 = 69.8 in my caculator. It comes back as 0 from do_div().

[jonsmirl@jonsmirl ~]$ dmesg | grep HPET
HPET: cap 0429b17f8086a201 period 0429b17f
HPET: period 0429b17f ns 0429b17f
HPET: period 0429b17f ns 00000000
Using HPET for base-timer
Using HPET for gettimeofday
[jonsmirl@jonsmirl ~]$


	hpetp->hp_period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
	    HPET_COUNTER_CLK_PERIOD_SHIFT;
printk(KERN_ERR "HPET: cap %016llx period %08lx\n", cap, hpetp->hp_period);

	ns = hpetp->hp_period;	/* femptoseconds, 10^-15 */
printk(KERN_ERR "HPET: period %08lx ns %08lx \n", hpetp->hp_period, ns);
	do_div(ns, 1000000);	/* convert to nanoseconds, 10^-9 */
printk(KERN_ERR "HPET: period %08lx ns %08lx \n", hpetp->hp_period, ns);
	printk(KERN_INFO "hpet%d: %ldns tick, %d %d-bit timers\n",
		hpetp->hp_which, ns, hpetp->hp_ntimer,
		cap & HPET_COUNTER_SIZE_MASK ? 64 : 32);
-- 
Jon Smirl
jonsmirl@gmail.com