From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: linux-i2c <linux-i2c@vger.kernel.org>,
Wolfram Sang <wsa@the-dreams.de>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Mani, Rajmohan" <rajmohan.mani@intel.com>,
Tomasz Figa <tfiga@chromium.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Bingbu Cao <bingbu.cao@intel.com>,
Chiranjeevi Rapolu <chiranjeevi.rapolu@intel.com>,
Hyungwoo Yang <hyungwoo.yang@intel.com>,
Linux Media Mailing List <linux-media@vger.kernel.org>
Subject: Re: [PATCH v9 1/7] ACPI: scan: Obtain device's desired enumeration power state
Date: Fri, 29 Jan 2021 18:45:22 +0200 [thread overview]
Message-ID: <20210129164522.GJ32460@paasikivi.fi.intel.com> (raw)
In-Reply-To: <CAJZ5v0hdG1W0D5E6GbrTDiAjMyC0mSgb3Z2WEBy3hhb4iJhDNw@mail.gmail.com>
Hi Rafael,
Thanks for the comments.
On Fri, Jan 29, 2021 at 03:07:57PM +0100, Rafael J. Wysocki wrote:
> On Fri, Jan 29, 2021 at 12:27 AM Sakari Ailus
> <sakari.ailus@linux.intel.com> wrote:
> >
> > Store a device's desired enumeration power state in struct
> > acpi_device_power_flags during acpi_device object's initialisation.
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > ---
> > drivers/acpi/scan.c | 6 ++++++
> > include/acpi/acpi_bus.h | 3 ++-
> > 2 files changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index 1d7a02ee45e05..b077c645c9845 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -987,6 +987,8 @@ static void acpi_bus_init_power_state(struct acpi_device *device, int state)
> >
> > static void acpi_bus_get_power_flags(struct acpi_device *device)
> > {
> > + unsigned long long pre;
> > + acpi_status status;
> > u32 i;
> >
> > /* Presence of _PS0|_PR0 indicates 'power manageable' */
> > @@ -1008,6 +1010,10 @@ static void acpi_bus_get_power_flags(struct acpi_device *device)
> > if (acpi_has_method(device->handle, "_DSW"))
> > device->power.flags.dsw_present = 1;
> >
> > + status = acpi_evaluate_integer(device->handle, "_PRE", NULL, &pre);
> > + if (ACPI_SUCCESS(status) && !pre)
> > + device->power.flags.allow_low_power_probe = 1;
>
> While this is what has been discussed and thanks for taking it into
> account, I'm now thinking that it may be cleaner to introduce a new
> object to return the deepest power state of the device in which it can
> be enumerated, say _DSE (Device State for Enumeration) such that 4
> means D3cold, 3 - D3hot and so on, so the above check can be replaced
> with something like
>
> status = acpi_evaluate_integer(device->handle, "_PRE", NULL, &dse);
s/_PRE/_DSE/
?
> if (ACPI_FAILURE(status))
ACPI_SUCCESS?
> device->power.state_for_enumeratin = dse;
>
> And then, it is a matter of comparing ->power.state_for_enumeratin
> with ->power.state and putting the device into D0 if the former is
> shallower than the latter.
>
> What do you think?
Sounds good. How about calling the function e.g.
acpi_device_resume_for_probe(), so runtime PM could be used to resume the
device if the function returns true?
--
Kind regards,
Sakari Ailus
next prev parent reply other threads:[~2021-01-29 16:48 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 8:15 [PATCH v8 0/6] Support running driver's probe for a device powered off Sakari Ailus
2020-09-03 8:15 ` [PATCH v8 1/6] i2c: Allow an ACPI driver to manage the device's power state during probe Sakari Ailus
2020-09-03 8:15 ` [PATCH v8 2/6] Documentation: ACPI: Document i2c-allow-low-power-probe _DSD property Sakari Ailus
2020-09-03 8:15 ` [PATCH v8 3/6] ACPI: Add a convenience function to tell a device is in low power state Sakari Ailus
[not found] ` <0c2d4728-6e32-ef93-8961-381fe36cfdaa@linux.intel.com>
2020-09-11 13:01 ` Sakari Ailus
2020-09-03 8:15 ` [PATCH v8 4/6] ov5670: Support probe whilst the device is in a " Sakari Ailus
2020-09-03 8:15 ` [PATCH v8 5/6] media: i2c: imx319: Support probe while the device is off Sakari Ailus
2020-09-03 8:15 ` [PATCH v8 6/6] at24: Support probing while off Sakari Ailus
2020-09-09 9:35 ` Bartosz Golaszewski
2020-09-09 11:11 ` Wolfram Sang
2020-09-09 11:56 ` Bartosz Golaszewski
2020-09-09 12:16 ` Sakari Ailus
2020-09-11 12:11 ` Sakari Ailus
2020-10-06 11:20 ` Tomasz Figa
2020-10-06 11:23 ` Tomasz Figa
2020-09-11 12:49 ` [PATCH v8 0/6] Support running driver's probe for a device powered off Luca Ceresoli
2020-09-11 13:01 ` Sakari Ailus
2020-09-14 7:58 ` Luca Ceresoli
[not found] ` <20200914094727.GM26842@paasikivi.fi.intel.com>
2020-09-14 16:49 ` Luca Ceresoli
2020-09-23 11:08 ` Sakari Ailus
2020-09-23 15:37 ` Luca Ceresoli
2020-09-26 12:38 ` Tomasz Figa
2020-09-27 19:39 ` Wolfram Sang
2020-09-27 19:44 ` Tomasz Figa
2020-09-28 14:17 ` Rafael J. Wysocki
2020-09-28 16:49 ` Tomasz Figa
2020-09-28 20:49 ` Sakari Ailus
2020-09-26 12:46 ` Tomasz Figa
2021-01-28 23:27 ` [PATCH v9 1/7] ACPI: scan: Obtain device's desired enumeration power state Sakari Ailus
[not found] ` <CAJZ5v0hdG1W0D5E6GbrTDiAjMyC0mSgb3Z2WEBy3hhb4iJhDNw@mail.gmail.com>
2021-01-29 16:45 ` Sakari Ailus [this message]
2021-01-29 16:57 ` Rafael J. Wysocki
2021-01-29 21:22 ` Sakari Ailus
2021-02-01 11:44 ` Rafael J. Wysocki
2021-01-28 23:27 ` [PATCH v9 2/7] i2c: Allow an ACPI driver to manage the device's power state during probe Sakari Ailus
2021-01-28 23:27 ` [PATCH v9 3/7] Documentation: ACPI: Document _PRE object usage for enum power state Sakari Ailus
2021-01-28 23:27 ` [PATCH v9 4/7] ACPI: Add a convenience function to tell a device is in low " Sakari Ailus
2021-01-28 23:27 ` [PATCH v9 5/7] ov5670: Support probe whilst the device is in a " Sakari Ailus
2021-01-28 23:27 ` [PATCH v9 6/7] media: i2c: imx319: Support probe while the device is off Sakari Ailus
2021-01-29 2:58 ` Bingbu Cao
2021-01-28 23:27 ` [PATCH v9 7/7] at24: Support probing while off Sakari Ailus
[not found] ` <CAMpxmJVTPgvxOVdTkmt4VjUnGabNBKauKF_DKtnnkV6O0QYTWA@mail.gmail.com>
[not found] ` <20210129121955.GH32460@paasikivi.fi.intel.com>
2021-02-01 8:57 ` Bartosz Golaszewski
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