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From: yegor_sub1@visionsystems.de (Yegor Yefremov)
To: linux-arm-kernel@lists.infradead.org
Subject: ks8695_gettimeoffset
Date: Mon, 27 Dec 2010 16:37:25 +0100	[thread overview]
Message-ID: <4D18B2B5.5000001@visionsystems.de> (raw)
In-Reply-To: <20101220193049.GI28157@n2100.arm.linux.org.uk>

Am 20.12.2010 20:30, schrieb Russell King - ARM Linux:
> On Mon, Dec 20, 2010 at 01:09:47PM -0600, Dick Hollenbeck wrote:
>> >From userspace, printing the return values from a rapid looping
>> sequence of calls to
>>
>>    clock_gettime( CLOCK_MONOTONIC, &now );
>>
>> leads me to believe that kernel function ks8695_gettimeoffset() is
>> not worth anything.
> 
> That'll be because clock_gettime(CLOCK_MONOTONIC) doesn't use the old
> gettimeoffset() method to correct the returned time - none of the POSIX
> timers use the old gettimeoffset() stuff, only gettimeofday() does.
> 
> Platforms really should be using the clocksource/clockevents code
> where ever possible, rather than selecting ARCH_USES_GETTIMEOFFSET.
> 
> Does someone with a KS8695-based platform want to have a go at
> converting it over to clocksource/clockevents?

Is it possible at all to implement clocksource/clockevents for KS8695? As Dick and "Register Description" already said you cannot read the time register, so clocksource->read cannot be implemented to return ticks elapsed. Or do I see it wrong? 

Is there any documentation for clocksource/clockevents? 

Best regards,
Yegor

  parent reply	other threads:[~2010-12-27 15:37 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-20 19:09 ks8695_gettimeoffset Dick Hollenbeck
2010-12-20 19:30 ` ks8695_gettimeoffset Russell King - ARM Linux
2010-12-20 19:37   ` ks8695_gettimeoffset Dick Hollenbeck
2010-12-27 15:37   ` Yegor Yefremov [this message]
2011-01-03  0:28     ` ks8695_gettimeoffset Russell King - ARM Linux
2011-01-03 19:55     ` ks8695_gettimeoffset avictor.za at gmail.com
2011-01-04  6:26       ` ks8695_gettimeoffset Dick Hollenbeck
2011-01-04  6:32         ` ks8695_gettimeoffset Dick Hollenbeck
  -- strict thread matches above, loose matches on Subject: below --
2010-12-20 19:32 ks8695_gettimeoffset Dick Hollenbeck

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