[PATCH 09/14] at91: switch pit timer to early platform devices

Jean-Christophe PLAGNIOL-VILLARD plagnioj at jcrosoft.com
Thu Apr 28 09:15:38 EDT 2011

On 12:34 Thu 28 Apr     , Russell King - ARM Linux wrote:
> On Thu, Apr 28, 2011 at 01:23:03PM +0200, Andrew Victor wrote:
> > hi,
> > 
> > > this will allow to specify the resources per soc
> > >
> > > as the 5series use a different start address for the pit
> > 
> > I really don't see the fascination with early platform_devices for timer.
> > A sys_timer is initialized way earlier, and there are surely cleaner
> > ways to just pass a "base address" through to the driver.
> > The interrupt is always AT91_ID_SYS on all chips, so there is no point
> > making it configurable.
> Me too - it looks like this early device stuff is heading in the
> wrong direction.
> There is a point when the kernel expects to have knowledge of the
> passing of time initialized, and that's when the system_timer->init
> callback is made.  At this point, everything is in place for the
> ticks to start, and some of the subsequent parts of the kernel may
> expect jiffies to be updating after this call has returned.
> Shoving stuff in other random places in the initialization order is
> asking for things to break - maybe not immediately, but down the
> line as things change in the generic parts of the code.
> Stick to using the callbacks provided for their defined purpose and
> life will be easier.  It'll also be a lot easier to consolidate some
> of the crap we've accumulated across each platform if everyone's
> doing stuff in the same way.
> And that's another reason to say no to this.  Please stop inventing new
> ways to do things unless you're prepared to provide it as a replacement
> for all the (ARM) platforms we have in the kernel.
Personally I do not change the current arm way

I init the timer during system_timer->init

I just the the early device their to pass the resources
but if switch all arm timer this way is fine to you I'm ready to do the whole

Best Regards,

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