From: Igor Stoppa <igor.stoppa@nokia.com>
To: "ext Woodruff, Richard" <r-woodruff2@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>, linux-omap-open-source@linux.omap.com
Subject: RE: [PATCH 28/28] omap2 clock: handle (almost) all clock autoidling viathe clock framework
Date: Mon, 20 Aug 2007 16:30:13 +0300 [thread overview]
Message-ID: <1187616613.7307.10.camel@localhost.localdomain> (raw)
In-Reply-To: <3B6D69C3A9EBCA4BA5DA60D91302742901AD7C91@dlee13.ent.ti.com>
On Mon, 2007-08-20 at 08:18 -0500, ext Woodruff, Richard wrote:
> One further note is in the 'ideal' model you should never have to
> control your I-CLK at all just your F-CLK. I'm sure our hardware people
> would be very pleased if the code moved in that direction (me too if it
> turned out to all work). They generally dislike the idea of the clock
> frame work as they feel it allows duplication of work the hardware can
> do if setup properly. Its APIs open up some choices which can nullify
> or reduce understanding of hardware capabilities. For OMAP1 there was no
> other way. For OMAP2/3 there are some options. I do very much like the
> frame work but do understand their points.
>
> Ideally, you set all idles at all levels and all async interrupt wake
> and use the PRCM interrupt to clear status at wake up time, then the
> system can handle all clocks based on dependency. Iclocks can be
> managed automatically. Fclocks should be dynamically controlled by
> drivers on a demand basis. This means some activity timers.
I'm not new to these concepts, however I find extremely hard to accept
the idea of using timers, since they assume to know what the duration of
the activity will be.
Could that work on an internet tablet?
For the tablet there is not really a set of use-cases like on a phone,
where you can have a closed set of fapplications and do some serious
profiling.
> When this
> does work the savings are really massive and dramatic. The catch in it
> is that one dependency break from a bad driver (sw or hw) at any of the
> multiple levels will stop it from working.
And how easy is it to trace that? All the refcounting seems to be done
in HW ...
--
Cheers, Igor
Igor Stoppa <igor.stoppa@nokia.com>
(Nokia Multimedia - CP - OSSO / Helsinki, Finland)
next prev parent reply other threads:[~2007-08-20 13:30 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-20 9:53 [PATCH 00/28] omap2 clock: framework generalization, cleanup Paul Walmsley
2007-08-20 9:53 ` [PATCH 01/28] omap2 clock: dsp_ick parent is dsp_fck, not core_ck Paul Walmsley
2007-08-20 9:53 ` [PATCH 02/28] omap2 clock: generalize initial clock rate setup: recalculate_root_clocks() Paul Walmsley
2007-08-20 9:53 ` [PATCH 03/28] omap2 clock: mark onchip_clks as __initdata Paul Walmsley
2007-08-20 9:53 ` [PATCH 05/28] omap2 clock: rename, add comment to omap2_mpu_recalc() Paul Walmsley
2007-08-20 9:53 ` [PATCH 06/28] omap2 clock: add clksel and clksel_rate data Paul Walmsley
2007-08-20 9:53 ` [PATCH 07/28] omap2 clock: init clksel clock parents to hardware reality at clock init Paul Walmsley
2007-08-20 12:27 ` [PATCH 07/28] omap2 clock: init clksel clock parents to hardwarereality " Woodruff, Richard
2007-08-21 6:49 ` Paul Walmsley
2007-08-20 9:53 ` [PATCH 08/28] omap2 clock: convert omap2_clksel_to_divisor and omap2_divisor_to_clksel to use new clksel struct Paul Walmsley
2007-08-20 9:53 ` [PATCH 09/28] omap2 clock: convert omap2_clksel_round_rate " Paul Walmsley
2007-08-20 9:53 ` [PATCH 10/28] omap2 clock: convert omap2_get_clksel " Paul Walmsley
2007-08-20 9:53 ` [PATCH 11/28] omap2 clock: convert omap2_clksel_get_src_field() " Paul Walmsley
2007-08-20 9:53 ` [PATCH 12/28] omap2 clock: stop using clk->src_offset in omap2_clk_set_rate() Paul Walmsley
2007-08-20 9:54 ` [PATCH 13/28] omap2 clock: stop using clk->src_offset in omap2_clk_set_parent() Paul Walmsley
2007-08-20 9:54 ` [PATCH 14/28] omap2 clock: clean out old code from omap2_clksel_recalc() Paul Walmsley
2007-08-20 9:54 ` [PATCH 15/28] omap2 clock: convert remaining clksel clocks to use omap2_clksel_recalc Paul Walmsley
2007-08-20 9:54 ` [PATCH 16/28] omap2 clock: remove all {src, rate}_offset fields from struct clk Paul Walmsley
2007-08-20 9:54 ` [PATCH 17/28] omap2 clock: use the struct clk round_rate field for clksel rate rounding code Paul Walmsley
2007-08-20 9:54 ` [PATCH 19/28] omap2 clock: drop RATE_CKCTL from all OMAP2 clocks Paul Walmsley
2007-08-20 9:54 ` [PATCH 20/28] omap2 clock: remove *_SEL* clock flags Paul Walmsley
2007-08-20 9:54 ` [PATCH 21/28] omap2 clock: call clock-specific enable/disable functions if present Paul Walmsley
2007-08-20 9:54 ` [PATCH 22/28] omap2 clock: use custom osc_ck enable/disable routines Paul Walmsley
2007-08-20 9:54 ` [PATCH 23/28] omap2 clock: use standard clk->enable/disable for APLLs Paul Walmsley
2007-08-20 9:54 ` [PATCH 24/28] omap2 clock: replace omap2_get_crystal_rate() with clock-specific recalc code Paul Walmsley
2007-08-20 9:54 ` [PATCH 25/28] omap2 clock: Standardize DPLL rate recalculation with struct dpll_data Paul Walmsley
2007-08-20 9:54 ` [PATCH 27/28] omap2 clock: add three missing clocks: gpmc_fck, sdma_{i, f}ck Paul Walmsley
2007-08-20 9:54 ` [PATCH 28/28] omap2 clock: handle (almost) all clock autoidling via the clock framework Paul Walmsley
2007-08-20 12:55 ` [PATCH 28/28] omap2 clock: handle (almost) all clock autoidling viathe " Woodruff, Richard
2007-08-21 7:04 ` Paul Walmsley
2007-08-21 17:29 ` Woodruff, Richard
2007-08-22 9:49 ` Paul Walmsley
2007-08-22 21:25 ` Woodruff, Richard
2007-08-27 7:39 ` Paul Walmsley
2007-08-30 22:21 ` Woodruff, Richard
2007-08-23 9:21 ` [PATCH 28/28] omap2 clock: handle (almost) all clock autoidlingviathe " Tuukka.Tikkanen
2007-08-27 7:56 ` Paul Walmsley
2007-08-27 14:13 ` Tuukka.Tikkanen
2007-08-20 13:18 ` [PATCH 28/28] omap2 clock: handle (almost) all clock autoidling viathe " Woodruff, Richard
2007-08-20 13:30 ` Igor Stoppa [this message]
2007-08-20 13:48 ` [PATCH 28/28] omap2 clock: handle (almost) all clockautoidling " Woodruff, Richard
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