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From: jon-hunter@ti•com (Jon Hunter)
To: linux-arm-kernel@lists•infradead.org
Subject: oprofile and ARM A9 hardware counter
Date: Mon, 7 May 2012 14:53:48 -0500	[thread overview]
Message-ID: <4FA8284C.7080803@ti.com> (raw)
In-Reply-To: <87ipg76hfm.fsf@ti.com>

Hi Kevin,

On 05/07/2012 12:15 PM, Kevin Hilman wrote:
> Jon Hunter <jon-hunter@ti•com> writes:
> 
>> Hi Will,
>>
>> On 04/26/2012 01:07 PM, Will Deacon wrote:
>>> On Wed, Apr 04, 2012 at 12:15:24PM +0100, Will Deacon wrote:
>>>> On Wed, Apr 04, 2012 at 12:29:49AM +0100, Paul Walmsley wrote:
>>>>>
>>>>> Part of the problem is that the clockdomain data for the emu_sys 
>>>>> clockdomain is wrong.  Here's something to try to fix it.  It might just 
>>>>> be enough to get it to work.
>>>>
>>>> Hmm, doesn't seem to work but I do see the following in dmesg when I try to
>>>> use perf:
>>>>
>>>>  powerdomain: waited too long for powerdomain emu_pwrdm to complete transition
>>>>
>>>> which is new with your patch.
>>>
>>> Sorry to nag, but does anybody have a clue where to go from here? I can
>>> start digging in the OMAP PM code, but it's all new territory for me.
>>
>> I did a little playing around with this today and I think that I have figured out why this was not working (see below). Please can you try the following patch? I tried this on top of your series for perf/omap4. 
>>
>> Paul, FYI. If this works for Will then I can re-base on top of the latest linux-omap and submit to the mailing list.
>>
>> Also, the above error about the emu_pwrdm is odd too. I noticed that the emu_pwrdm is always in the transitioning state. And when I say always, I mean that even if I check the power domain state while u-boot is running it is in the transitioning state. So even before the kernel starts. 
>>
>> Cheers
>> Jon 
>>
>> From 9137ff9c1b382232de7443db0b51b7555846fb62 Mon Sep 17 00:00:00 2001
>> From: Jon Hunter <jon-hunter@ti•com>
>> Date: Fri, 4 May 2012 16:48:45 -0500
>> Subject: [PATCH] ARM: OMAP4: Disable auto enable for EMU CLKDM
>>
>> The flag CLKDM_CAN_HWSUP allows the clock-domain to automatically transition
>> to the enabled and disabled state. This means that as soon as we force a
>> software wake-up on the clock domain, the clock domain will be allowed to idle
>> and put back into the hardware auto state. For the EMU clock domain this is not
>> what we want. We want to keep the clock domain in the software wakeup state
>> while the clock domain is being used and put it back in to the hardware auto
>> state when we have finished using the clock domain.
>>
>> Signed-off-by: Jon Hunter <jon-hunter@ti•com>
> 
> With this patch, how is the clkdm ever idled?

It does not! Sorry, I was so engrossed with figuring out why the EMU
clkdm was being idled as soon as it was enabled, I forgot to check if is
ever disabled once we terminated perf :-(

> IIUC, your patch will get PMU interrupts working, but similarily to
> previous patches in this thread, it works because it *never* allows the
> EMU clkdm to idle.  This is not a mergeable solution because it will not
> allow CORE retention (and thus full-chip retention.)

Right!

> What we need is a solution that allows the clkdm to idle, and then to be
> reinitialzed when it wakes up.  Due to the way (I understand) resets in
> the debugss, allowing the clkdm to idle will cause a reset, so the
> PMU/CTI interrupts need to be reinitialzied after wakeup.

Yes exactly I see that now. I have prototyped the 3 patches and this is
working AND the EMU clkdm does go back to idle. I can send out to the
list for review.

> Kevin
> 
> P.S. Please note there is also already a different fix in mainline for
> the EMU clkdm data from Paul which adds the force wakeup flag and
> removes the DISABLE_AUTO flag[1] (but leaves the ENABLE_AUTO flag,
> because the hardware is capable.)

Hmmm ... yes saw this, and you will have to excuse me as I don't fully
follow the logic here. In fact, I am thinking we want the opposite ;-)

>From looking, into this it seems to me that when PMU is running we want
the EMU clock domain in software-wakeup state and when PMU is not
running we want in the hardware auto state. By keeping the ENABLE_AUTO
flag set, as soon as we enable the clock domain it is put right back
into the HW_AUTO state and hence PMU is not working (see _enable()
function in arch/arm/mach-omap2/omap_hwmod.c)

So really what I think we want is to remove the ENABLE_AUTO flag to keep
the clock domain in software wake-up and use the DISABLE_AUTO flag to
put the clock domain back in HW_AUTO (note this requires a patch to
perform this 2nd part).

Cheers
Jon

  reply	other threads:[~2012-05-07 19:53 UTC|newest]

Thread overview: 134+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAAO=S0+L2Q1YZC-pfm2Lz8jPooTeHYOMaZbtRgHYFoL_m7rvhA@mail.gmail.com>
     [not found] ` <4F0B182D.7060507@us.ibm.com>
2012-01-09 22:49   ` oprofile and ARM A9 hardware counter Will Deacon
2012-01-09 23:30     ` Ming Lei
2012-01-10  0:46       ` stephane eranian
2012-01-18  4:18         ` Ming Lei
2012-01-18  9:33           ` Ming Lei
2012-01-18 11:39             ` Shilimkar, Santosh
2012-01-18 12:24               ` Ming Lei
2012-01-18 12:33                 ` Shilimkar, Santosh
2012-04-03  9:25                   ` Will Deacon
2012-04-03  9:42                     ` Shilimkar, Santosh
2012-04-03  9:47                       ` Will Deacon
2012-04-03 10:01                         ` Shilimkar, Santosh
2012-04-03 12:34                           ` Will Deacon
2012-04-03 12:41                             ` Shilimkar, Santosh
2012-04-03 14:27                             ` Kevin Hilman
2012-04-03 16:07                               ` Will Deacon
2012-04-03 23:14                                 ` Kevin Hilman
2012-04-03 23:29                                   ` Paul Walmsley
2012-04-04  3:42                                     ` Ming Lei
2012-04-04 11:15                                     ` Will Deacon
2012-04-26 18:07                                       ` Will Deacon
2012-04-30 22:25                                         ` Kevin Hilman
2012-05-07 17:27                                           ` Ming Lei
2012-05-04 22:17                                         ` Jon Hunter
2012-05-07 17:15                                           ` Kevin Hilman
2012-05-07 19:53                                             ` Jon Hunter [this message]
2012-05-07 23:28                                               ` Kevin Hilman
2012-05-08 11:01                                                 ` Cousson, Benoit
2012-05-08 11:23                                                   ` Jean Pihet
2012-05-08 12:37                                                     ` Cousson, Benoit
2012-05-08 13:18                                                       ` Jean Pihet
2012-05-08 14:00                                                         ` Kevin Hilman
2012-05-08 14:03                                                           ` Cousson, Benoit
2012-05-08 16:18                                                             ` Kevin Hilman
2012-05-08 19:51                                                               ` Jon Hunter
2012-05-08 21:28                                                                 ` Kevin Hilman
2012-05-08 22:20                                                                   ` Jon Hunter
2012-05-08 22:12                                                                 ` Ming Lei
2012-05-08 17:31                                                   ` Jon Hunter
2012-05-08 21:22                                                     ` Kevin Hilman
2012-05-08 23:59                                                       ` Jon Hunter
2012-05-09 10:58                                                       ` Cousson, Benoit
2012-05-09 18:04                                                         ` Jon Hunter
2012-05-09 19:28                                                           ` Jon Hunter
2012-05-09 21:45                                                             ` Jon Hunter
2012-05-10  8:44                                                               ` Will Deacon
2012-05-10  9:12                                                                 ` stephane eranian
2012-05-10 18:55                                                                 ` Jon Hunter
2012-05-11 12:25                                                                   ` Will Deacon
2012-05-11 13:47                                                                     ` Jon Hunter
2012-05-11 13:49                                                                       ` Will Deacon
2012-05-11 14:52                                                                         ` Jon Hunter
2012-05-11 15:02                                                                           ` Will Deacon
2012-05-11 16:31                                                                             ` Jon Hunter
2012-05-11 16:38                                                                               ` Will Deacon
2012-05-11 23:51                                                                                 ` Jon Hunter
2012-05-15 13:52                                                                                   ` Will Deacon
2012-05-10 14:12                                                               ` Kevin Hilman
2012-05-10 19:05                                                                 ` Jon Hunter
2012-05-10  6:59                                                         ` Santosh Shilimkar
2012-05-08 21:50                                                 ` Paul Walmsley
2012-04-04  0:00                             ` Paul Walmsley
2012-04-04 11:07                               ` Will Deacon
2012-01-18  9:54           ` stephane eranian
2012-01-18 10:07             ` Ming Lei
2012-01-18 21:58               ` stephane eranian
2012-01-19  1:21                 ` Ming Lei
2012-01-19 11:34                   ` stephane eranian
2012-01-19 12:45                     ` Ming Lei
2012-01-19 12:51                       ` stephane eranian
2012-01-19 12:55                         ` stephane eranian
2012-01-19 13:14                         ` Ming Lei
2012-01-19 13:26                           ` Ming Lei
2012-01-19 13:32                             ` stephane eranian
2012-01-19 13:51                               ` Ming Lei
2012-01-19 17:07                                 ` stephane eranian
2012-01-20 13:47                                   ` stephane eranian
2012-01-21  3:25                                     ` Ming Lei
2012-01-21  9:16                                       ` stephane eranian
2012-01-27 12:13                                         ` Will Deacon
2012-01-27 12:45                                           ` stephane eranian
2012-01-27 12:56                                           ` Måns Rullgård
2012-01-27 13:28                                             ` Will Deacon
2012-01-27 13:32                                               ` stephane eranian
2012-01-27 13:47                                               ` Måns Rullgård
2012-01-27 13:56                                                 ` Will Deacon
2012-01-27 14:05                                                   ` Måns Rullgård
2012-01-27 14:09                                               ` Ming Lei
2012-01-27 15:45                                                 ` stephane eranian
2012-01-27 15:54                                                   ` Will Deacon
2012-01-27 15:57                                                     ` stephane eranian
2012-01-27 16:59                                                       ` Will Deacon
2012-01-27 17:03                                                         ` stephane eranian
2012-01-27 17:10                                                           ` Will Deacon
2012-01-27 17:16                                                             ` stephane eranian
2012-01-29 17:36                                                               ` stephane eranian
2012-01-30  9:40                                                                 ` Ming Lei
2012-01-30 10:24                                                                   ` stephane eranian
2012-01-30 13:43                                                                     ` stephane eranian
2012-01-30 14:49                                                                       ` Ming Lei
2012-01-30 16:02                                                                         ` stephane eranian
2012-01-30 16:08                                                                           ` Måns Rullgård
2012-01-30 17:15                                                                             ` stephane eranian
2012-01-30 17:24                                                                               ` Will Deacon
2012-01-30 17:45                                                                                 ` stephane eranian
2012-01-30 19:14                                                                                   ` Will Deacon
2012-01-30 20:45                                                                                     ` stephane eranian
2012-03-07  2:49                                                     ` Ming Lei
2012-03-07  9:48                                                       ` Will Deacon
2012-01-27 14:06                                           ` Ming Lei
2012-01-18 10:18             ` Russell King - ARM Linux
     [not found] <1328578047.1724.17.camel@dave-Dell-System-XPS-L502X>
     [not found] ` <CAMQu2gwfo5JXAqQaLUNs7C7J3TUhEO2zOcyD0Rk-D_O61Yrfag@mail.gmail.com>
     [not found]   ` <CAMsRxfLNBbQO5XF+EHJqNsnW+s=ay3mjSV5dh=sxdwzktUu03g@mail.gmail.com>
     [not found]     ` <CAMQu2gzfNAwtf1c6jrTZpfGMSqBgBrQKmFTeCFzbvMh9ESBDUg@mail.gmail.com>
     [not found]       ` <CAMsRxfKR1ODH56BtcUT5Dv6qOVEYGVheEcW9ugXsZmLKok==bg@mail.gmail.com>
2012-02-07 10:53         ` Shilimkar, Santosh
2012-02-07 11:09           ` Shilimkar, Santosh
2012-02-07 11:25             ` stephane eranian
2012-02-07 11:39               ` Shilimkar, Santosh
2012-02-07 11:59                 ` stephane eranian
2012-02-07 15:30                   ` Will Deacon
2012-02-08  2:24                   ` Ming Lei
2012-02-15 16:38                     ` Peter Zijlstra
2012-02-16 10:25                       ` Ming Lei
2012-02-16 15:00                         ` Will Deacon
2012-02-16 16:12                           ` Ming Lei
2012-02-16 16:19                             ` Peter Zijlstra
2012-02-16 16:37                               ` Ming Lei
2012-02-16 18:08                                 ` Will Deacon
2012-02-17  5:24                                   ` Ming Lei
2012-02-17 10:26                                     ` Will Deacon
2012-02-20  3:19                                       ` Ming Lei
2012-02-20  9:44                                         ` Will Deacon
2012-02-13 13:15                   ` Will Deacon
     [not found]           ` <1329508513.1858.15.camel@dave-Dell-System-XPS-L502X>
2012-02-18  4:31             ` Shilimkar, Santosh
2012-04-03  9:44               ` Will Deacon
2012-04-03  9:47                 ` Shilimkar, Santosh
     [not found] ` <CACVXFVN0E_deS2d50mfufO5QZSwh=34BppCL++oxtc3nfN_ugA@mail.gmail.com>
     [not found]   ` <1328664644.1678.15.camel@dave-Dell-System-XPS-L502X>
2012-02-09 20:05     ` David A. Long

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