From: Sven van Ashbrook <svenva@chromium.org>
To: "Limonciello, Mario" <Mario.Limonciello@amd.com>
Cc: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>,
Hans de Goede <hdegoede@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
"S-k, Shyam-sundar" <Shyam-sundar.S-k@amd.com>,
"rrangel@chromium.org" <rrangel@chromium.org>,
"platform-driver-x86@vger.kernel.org"
<platform-driver-x86@vger.kernel.org>,
Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>,
Rafael J Wysocki <rjw@rjwysocki.net>,
Rajat Jain <rajatja@google.com>,
David E Box <david.e.box@intel.com>,
Mark Gross <markgross@kernel.org>
Subject: Re: [PATCH v1] platform/x86: intel_pmc_core: promote S0ix failure warn() to WARN()
Date: Mon, 31 Oct 2022 21:38:42 -0400 [thread overview]
Message-ID: <CAG-rBijSASfbfWQNarjGqj2UxQDOSdwM-qj5YA5A9ur=DNJf-g@mail.gmail.com> (raw)
In-Reply-To: <MN0PR12MB610109F448E3FC8CE71FBA76E2379@MN0PR12MB6101.namprd12.prod.outlook.com>
On Mon, Oct 31, 2022 at 3:39 PM Limonciello, Mario
<Mario.Limonciello@amd.com> wrote:
>
> Just thinking about it a little bit more, it could be a lot nicer to have something like:
>
> /sys/power/suspend_stats/last_hw_deepest_state
While I agree that reporting through a framework is generally better
than getting infrastructure to grep for specific strings, I believe
that a simple sysfs file is probably too simplistic.
1. We need more sophisticated reporting than just last_hw_deepest_state:
- sometimes the system enters the deep state we want, yet after a
while moves back up and gets "stuck" in an intermediate state (below
S0). Or, the system enters the deep state we want, but moves back to
S0 after a time without apparent reason. These platform-dependent
failures are not so easily describable in a generic framework.
- ChromeOS in particular has multiple independent S0ix / S3 / s2idle
failure report sources. We have the kernel warning above; also our
Embedded Controller monitors suspend failure cases which the simple
kernel warning cannot catch, reported through a separate WARN_ONCE().
2. A simple sysfs file will need to be polled by the infrastructure
after every suspend; it would be preferable to have some signal or
callback which the infrastructure could register itself with.
The generic infrastructure to support this sounds like quite a bit of
work, and for what gain? Compared to simply matching a log string and
sending the whole dmesg if there's a match.
Is the light worth the candle?
Sven
next prev parent reply other threads:[~2022-11-01 1:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-27 15:19 [PATCH v1] platform/x86: intel_pmc_core: promote S0ix failure warn() to WARN() Sven van Ashbrook
2022-10-27 15:40 ` Hans de Goede
2022-10-27 15:47 ` Limonciello, Mario
2022-10-27 15:51 ` Sven van Ashbrook
[not found] ` <CAE2upjS6qRGRcuVYuAB5DMf66A7VcfCKKYEkpsr1My7RnKDFtQ@mail.gmail.com>
2022-10-29 4:11 ` Sven van Ashbrook
2022-10-31 19:39 ` Limonciello, Mario
2022-10-31 20:15 ` Hans de Goede
2022-10-31 20:20 ` Sven van Ashbrook
[not found] ` <CACK8Z6E7=xt118d47FTpmgKHgUBgH48FQzTi5iL90C3MjHb-3Q@mail.gmail.com>
2022-10-31 20:55 ` Limonciello, Mario
2022-11-01 17:24 ` Sven van Ashbrook
2022-11-01 20:30 ` David E. Box
2022-11-01 1:38 ` Sven van Ashbrook [this message]
2022-11-01 1:58 ` Mario Limonciello
2022-11-01 13:50 ` Sven van Ashbrook
2022-10-27 16:37 ` David E. Box
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