From: jon-hunter@ti•com (Jon Hunter)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC v2 13/18] ARM: OMAP2+: AM33XX: timer: Interchance clkevt and clksrc timers
Date: Wed, 30 Jan 2013 11:49:34 -0600 [thread overview]
Message-ID: <51095D2E.1040708@ti.com> (raw)
In-Reply-To: <51095CDA.9090701@ti.com>
On 01/30/2013 11:48 AM, Jon Hunter wrote:
>
> On 01/24/2013 04:30 PM, Jon Hunter wrote:
>> Hi Vaibhav,
>>
>> On 12/31/2012 07:07 AM, Vaibhav Bedia wrote:
>>> AM33XX has two timers (DTIMER0/1) in the WKUP domain.
>>> On GP devices the source of DMTIMER0 is fixed to an
>>> inaccurate internal 32k RC oscillator and this makes
>>> the DMTIMER0 practically either as a clocksource or
>>> as clockevent.
>>>
>>> Currently the timer instance in WKUP domain is used
>>> as the clockevent and the timer in non-WKUP domain
>>> as the clocksource. DMTIMER1 in WKUP domain can keep
>>> running in suspend from a 32K clock fed from external
>>> OSC and can serve as the persistent clock for the kernel.
>>> To enable this, interchange the timers used as clocksource
>>> and clockevent for AM33XX.
>>
>> I have been thinking about this some more. In the case where we are
>> using gptimers for both clock-events and clock-source (on both AM33xx
>> and OMAP) and I am wondering if it makes sense to switch the timers so
>> that we use the always-on timer for clock-source and a different one
>> from clock-events.
>>
>> For OMAP, if we are not using the 32k-sync for clock-source, then we are
>> never going to achieve low power states during idle as we will always
>> have one gptimer running. And in this case, to your point below, it
>> would be better to use the always-on for clock-source so that in suspend
>> we can at least hit low power states and maintain time.
>
> I have posted a patch today [1] that I hope will address this issue for
> you. Can you give that a try?
By the way, this need to be applied on top of the fix I sent yesterday
to pass the property.
Cheers
Jon
next prev parent reply other threads:[~2013-01-30 17:49 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-31 13:06 [RFC v2 00/18] ARM: OMAP2+: AM33XX: Add suspend-resume support Vaibhav Bedia
2012-12-31 13:06 ` [RFC v2 01/18] mailbox: OMAP2+: Add support for AM33XX Vaibhav Bedia
2013-01-01 18:25 ` Tony Lindgren
2013-01-02 11:09 ` Bedia, Vaibhav
2013-01-08 13:53 ` Santosh Shilimkar
2013-01-09 5:16 ` Bedia, Vaibhav
2012-12-31 13:06 ` [RFC v2 02/18] mailbox: Add an API for flushing the FIFO Vaibhav Bedia
2013-01-08 13:56 ` Santosh Shilimkar
2013-01-09 5:16 ` Bedia, Vaibhav
2012-12-31 13:06 ` [RFC v2 03/18] memory: emif: Move EMIF related header file to include/linux/ Vaibhav Bedia
2013-01-08 14:04 ` Santosh Shilimkar
2013-01-09 5:31 ` Bedia, Vaibhav
2012-12-31 13:06 ` [RFC v2 04/18] ARM: OMAP2+: AM33XX: CM: Get rid of unncessary header inclusions Vaibhav Bedia
2013-01-08 15:00 ` Santosh Shilimkar
2012-12-31 13:06 ` [RFC v2 05/18] ARM: OMAP2+: AM33XX: CM/PRM: Use __ASSEMBLER__ macros in header files Vaibhav Bedia
2013-01-08 15:01 ` Santosh Shilimkar
2013-01-09 5:31 ` Bedia, Vaibhav
2012-12-31 13:06 ` [RFC v2 06/18] ARM: OMAP2+: AM33XX: hwmod: Register OCMC RAM hwmod Vaibhav Bedia
2013-01-08 15:04 ` Santosh Shilimkar
2012-12-31 13:07 ` [RFC v2 07/18] ARM: OMAP2+: AM33XX: hwmod: Update TPTC0 hwmod with the right flags Vaibhav Bedia
2013-01-08 15:05 ` Santosh Shilimkar
2013-01-09 6:02 ` Bedia, Vaibhav
2013-02-11 23:33 ` Kevin Hilman
2013-02-13 10:56 ` Bedia, Vaibhav
2012-12-31 13:07 ` [RFC v2 08/18] ARM: OMAP2+: AM33XX: hwmod: Fixup cpgmac0 hwmod entry Vaibhav Bedia
2013-01-08 15:08 ` Santosh Shilimkar
2012-12-31 13:07 ` [RFC v2 09/18] ARM: OMAP2+: AM33XX: hwmod: Update the WKUP-M3 hwmod with reset status bit Vaibhav Bedia
2013-01-08 15:09 ` Santosh Shilimkar
2012-12-31 13:07 ` [RFC v2 10/18] ARM: OMAP2+: AM33XX: Update the hardreset API Vaibhav Bedia
2013-01-08 15:10 ` Santosh Shilimkar
2012-12-31 13:07 ` [RFC v2 11/18] ARM: DTS: AM33XX: Add nodes for OCMC RAM and WKUP-M3 Vaibhav Bedia
2013-01-08 15:12 ` Santosh Shilimkar
2012-12-31 13:07 ` [RFC v2 12/18] ARM: OMAP2+: timer: Add suspend-resume callbacks for clockevent device Vaibhav Bedia
2013-01-08 15:15 ` Santosh Shilimkar
2013-01-11 4:37 ` Bedia, Vaibhav
2013-01-17 18:45 ` Jon Hunter
2013-01-18 5:25 ` Santosh Shilimkar
2013-01-21 7:22 ` Bedia, Vaibhav
2013-01-30 17:46 ` Jon Hunter
2013-01-31 11:17 ` Bedia, Vaibhav
2013-01-17 18:40 ` Jon Hunter
2013-01-21 7:22 ` Bedia, Vaibhav
2012-12-31 13:07 ` [RFC v2 13/18] ARM: OMAP2+: AM33XX: timer: Interchance clkevt and clksrc timers Vaibhav Bedia
2013-01-08 15:17 ` Santosh Shilimkar
2013-01-09 5:31 ` Bedia, Vaibhav
2013-01-17 19:09 ` Jon Hunter
2013-01-24 22:30 ` Jon Hunter
2013-01-30 17:48 ` Jon Hunter
2013-01-30 17:49 ` Jon Hunter [this message]
2013-01-31 11:29 ` Bedia, Vaibhav
2012-12-31 13:07 ` [RFC v2 14/18] ARM: OMAP2+: AM33XX: control: Add some control module registers and APIs Vaibhav Bedia
2013-01-08 15:21 ` Santosh Shilimkar
2013-01-09 5:38 ` Bedia, Vaibhav
2013-01-09 7:31 ` Santosh Shilimkar
2013-01-09 9:37 ` Bedia, Vaibhav
2013-01-09 9:53 ` Santosh Shilimkar
2012-12-31 13:07 ` [RFC v2 15/18] ARM: OMAP2+: AM33XX: Add assembly code for PM operations Vaibhav Bedia
2012-12-31 13:07 ` [RFC v2 16/18] ARM: OMAP2+: AM33XX: Basic suspend resume support Vaibhav Bedia
2013-01-17 14:27 ` Peter Korsgaard
2013-01-21 10:37 ` Bedia, Vaibhav
2013-01-22 12:50 ` Peter Korsgaard
2013-02-12 1:27 ` Kevin Hilman
2013-02-13 13:43 ` Bedia, Vaibhav
2013-02-18 16:11 ` Kevin Hilman
2013-02-20 9:21 ` Bedia, Vaibhav
2013-02-20 14:30 ` Kevin Hilman
2013-04-03 11:52 ` Daniel Mack
2013-04-04 8:47 ` Bedia, Vaibhav
2012-12-31 13:07 ` [RFC v2 17/18] ARM: OMAP2+: AM33XX: Select Mailbox when PM is enabled Vaibhav Bedia
2013-01-08 15:22 ` Santosh Shilimkar
2013-01-09 5:38 ` Bedia, Vaibhav
2012-12-31 13:07 ` [RFC v2 18/18] ARM: OMAP2+: AM33XX: Hookup AM33XX PM code into OMAP builds Vaibhav Bedia
2013-01-08 15:31 ` [RFC v2 00/18] ARM: OMAP2+: AM33XX: Add suspend-resume support Santosh Shilimkar
2013-01-09 5:38 ` Bedia, Vaibhav
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