From: john stultz <johnstul@us.ibm.com>
To: Guan Xuetao <guanxuetao@mprc.pku.edu.cn>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: RE: [PATCHv1 09/12] unicore32 core architecture: timer and time
Date: Mon, 03 Jan 2011 11:58:53 -0800 [thread overview]
Message-ID: <1294084733.2571.54.camel@work-vm> (raw)
In-Reply-To: <00ef01cbab0a$66bfce60$343f6b20$@mprc.pku.edu.cn>
On Mon, 2011-01-03 at 13:52 +0800, Guan Xuetao wrote:
> > When using clocksource_register_hz(&cksrc_puv3_oscr, CLOCK_TICK_RATE ),
> > the shift value become 0, and mult value become 0x838a91a7, and the system will be broken
> > after printing "Switching to clocksource oscr".
> >
> > When using clocksource_register_khz(&cksrc_puv3_oscr, CLOCK_TICK_RATE ),
> > the shift value become 0, and mult value become 0x4359611, and the system will run smoothly,
> > but timer interrupt seems too frequently. Perhaps it is 4 times faster.
> >
> > For comparison, originally, when shift value is set to 0x12, the mult value become 1175e5e.
> >
>
> The error is the implementation of do_div() function.
> When replacing the arch-specific div64.h with asm-generic/div64.h, clocksource_rigister_hz() works.
Oh great! You had me worried I had a bug in the mult/shift calculation.
Great to hear all is working now! If you run into other clock/time
related troubles, please let me know.
thanks
-john
prev parent reply other threads:[~2011-01-03 19:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-25 18:54 [PATCHv1 09/12] unicore32 core architecture: timer and time Guan Xuetao
2010-12-25 18:54 ` Guan Xuetao
2010-12-27 21:27 ` john stultz
2011-01-02 9:47 ` Guan Xuetao
2011-01-02 9:47 ` Guan Xuetao
2011-01-03 5:52 ` Guan Xuetao
2011-01-03 5:52 ` Guan Xuetao
2011-01-03 19:58 ` john stultz [this message]
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