From: Kukjin Kim <kgene.kim@samsung.com>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org,
Sangbeom Kim <sbkim73@samsung.com>
Subject: Re: [PATCH 2/2] ARM: S5P: Add 64bit PWM timer counter for sched_clock
Date: Sun, 29 May 2011 18:45:17 -0700 [thread overview]
Message-ID: <4DE2F6AD.5000000@samsung.com> (raw)
In-Reply-To: <20110528071710.GU24876@n2100.arm.linux.org.uk>
On 05/28/11 00:17, Russell King - ARM Linux wrote:
> On Fri, May 27, 2011 at 03:10:10PM -0700, Kukjin Kim wrote:
>> From: Sangbeom Kim<sbkim73@samsung.com>
>>
>> Basically, PWM timer works with 33Mhz on S5P SoCs and counter
>> overflow every 128 secs. So it is needed 64-bit counter for
>> supporting proper sched_clock() by 32-bit timer. This patch
>> handle overflow control and can solve the problem of suspend
>> to resume
>
> NAK.
>
> This patch is a backwards step, and adds a hell of a lot of complexity
> which should already be dealt with in generic code.
>
Yes, I agree :)
> What is "problem of suspend to resume" exactly?
>
Could you please check below?
<6>[ 43.125215] request_suspend_state: sleep (0->3) ...(snip)...
<6>[ 43.385289] PM: Syncing filesystems ... done.
<4>[ 43.391553] Freezing user space processes ...(snip)...
<4>[ 43.408781] Freezing remaining freezable tasks ...(snip)...
<6>[ 43.558009] PM: suspend of devices complete ...(snip)...
<6>[ 43.558514] PM: late suspend of devices complete ...(snip)...
<7>[ 128.784602] S5P_WAKEUP_STAT 0x1
<7>[ 128.784602] EINT_PEND 0x6, 0x0, 0x60, 0x40
<6>[ 0.000319] PM: early resume of devices complete ...(snip)...
<6>[ 0.000595] wakeup wake lock: gpio_input
<6>[ 0.321657] PM: resume of devices complete ...(snip)...
<4>[ 0.321976] Restarting tasks ...
<6>[ 0.325617] request_suspend_state: wakeup (3->0) ...(snip)...
<4>[ 0.342688] done.
<6>[ 0.342917] suspend: exit suspend, ret = 0 ...(snip)...
Yeah, the timestamp jumped back after a suspend/resume cycle.
Do you have any idea about that?
Thanks.
Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.
WARNING: multiple messages have this Message-ID (diff)
From: kgene.kim@samsung.com (Kukjin Kim)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] ARM: S5P: Add 64bit PWM timer counter for sched_clock
Date: Sun, 29 May 2011 18:45:17 -0700 [thread overview]
Message-ID: <4DE2F6AD.5000000@samsung.com> (raw)
In-Reply-To: <20110528071710.GU24876@n2100.arm.linux.org.uk>
On 05/28/11 00:17, Russell King - ARM Linux wrote:
> On Fri, May 27, 2011 at 03:10:10PM -0700, Kukjin Kim wrote:
>> From: Sangbeom Kim<sbkim73@samsung.com>
>>
>> Basically, PWM timer works with 33Mhz on S5P SoCs and counter
>> overflow every 128 secs. So it is needed 64-bit counter for
>> supporting proper sched_clock() by 32-bit timer. This patch
>> handle overflow control and can solve the problem of suspend
>> to resume
>
> NAK.
>
> This patch is a backwards step, and adds a hell of a lot of complexity
> which should already be dealt with in generic code.
>
Yes, I agree :)
> What is "problem of suspend to resume" exactly?
>
Could you please check below?
<6>[ 43.125215] request_suspend_state: sleep (0->3) ...(snip)...
<6>[ 43.385289] PM: Syncing filesystems ... done.
<4>[ 43.391553] Freezing user space processes ...(snip)...
<4>[ 43.408781] Freezing remaining freezable tasks ...(snip)...
<6>[ 43.558009] PM: suspend of devices complete ...(snip)...
<6>[ 43.558514] PM: late suspend of devices complete ...(snip)...
<7>[ 128.784602] S5P_WAKEUP_STAT 0x1
<7>[ 128.784602] EINT_PEND 0x6, 0x0, 0x60, 0x40
<6>[ 0.000319] PM: early resume of devices complete ...(snip)...
<6>[ 0.000595] wakeup wake lock: gpio_input
<6>[ 0.321657] PM: resume of devices complete ...(snip)...
<4>[ 0.321976] Restarting tasks ...
<6>[ 0.325617] request_suspend_state: wakeup (3->0) ...(snip)...
<4>[ 0.342688] done.
<6>[ 0.342917] suspend: exit suspend, ret = 0 ...(snip)...
Yeah, the timestamp jumped back after a suspend/resume cycle.
Do you have any idea about that?
Thanks.
Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.
next prev parent reply other threads:[~2011-05-30 1:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-27 22:10 [PATCH 1/2] ARM: S5P: Cleanup s5p-time for HRTimer Kukjin Kim
2011-05-27 22:10 ` Kukjin Kim
2011-05-27 22:10 ` [PATCH 2/2] ARM: S5P: Add 64bit PWM timer counter for sched_clock Kukjin Kim
2011-05-27 22:10 ` Kukjin Kim
2011-05-28 7:17 ` Russell King - ARM Linux
2011-05-28 7:17 ` Russell King - ARM Linux
2011-05-30 1:45 ` Kukjin Kim [this message]
2011-05-30 1:45 ` Kukjin Kim
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4DE2F6AD.5000000@samsung.com \
--to=kgene.kim@samsung.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=sbkim73@samsung.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.