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References: <20220912221317.2775651-1-rrangel@chromium.org>
 <20220912160931.v2.7.I8af4282adc72eb9f247adcd03676a43893a020a6@changeid> <YyFslxMchzntebVb@black.fi.intel.com>
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From:   Raul Rangel <rrangel@chromium.org>
Date:   Wed, 14 Sep 2022 15:00:20 -0600
Message-ID: <CAHQZ30AhQOxUBtbs8enUnGkBbtPYAN=_6vDV-9CcuMLMypZhtg@mail.gmail.com>
Subject: Re: [PATCH v2 07/13] i2c: acpi: Use ACPI wake capability bit to set wake_irq
To:     Mika Westerberg <mika.westerberg@linux.intel.com>
Cc:     Linux ACPI <linux-acpi@vger.kernel.org>,
        linux-input <linux-input@vger.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        "jingle.wu" <jingle.wu@emc.com.tw>,
        "Limonciello, Mario" <mario.limonciello@amd.com>,
        Tim Van Patten <timvp@google.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Hans de Goede <hdegoede@redhat.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Wolfram Sang <wsa@kernel.org>,
        "open list:I2C SUBSYSTEM HOST DRIVERS" <linux-i2c@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Sep 13, 2022 at 11:54 PM Mika Westerberg
<mika.westerberg@linux.intel.com> wrote:
>
> Hi,
>
> On Mon, Sep 12, 2022 at 04:13:11PM -0600, Raul E Rangel wrote:
> > Device tree already has a mechanism to pass the wake_irq. It does this
> > by looking for the wakeup-source property and setting the
> > I2C_CLIENT_WAKE flag. This CL adds the ACPI equivalent. It uses the
> > ACPI interrupt wake flag to determine if the interrupt can be used to
> > wake the system. Previously the i2c drivers had to make assumptions and
> > blindly enable the wake IRQ. This can cause spurious wake events. e.g.,
> > If there is a device with an Active Low interrupt and the device gets
> > powered off while suspending, the interrupt line will go low since it's
> > no longer powered and wakes the system. For this reason we should
> > respect the board designers wishes and honor the wake bit defined on the
> > interrupt.
> >
> > Signed-off-by: Raul E Rangel <rrangel@chromium.org>
> > ---
> >
> > Changes in v2:
> > - Look at wake_cabple bit for IRQ/Interrupt resources
> >
> >  drivers/i2c/i2c-core-acpi.c | 37 ++++++++++++++++++++++++++++---------
> >  drivers/i2c/i2c-core-base.c |  6 +++++-
> >  drivers/i2c/i2c-core.h      |  4 ++--
> >  3 files changed, 35 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
> > index c762a879c4cc6b..c3d69b287df824 100644
> > --- a/drivers/i2c/i2c-core-acpi.c
> > +++ b/drivers/i2c/i2c-core-acpi.c
> > @@ -137,6 +137,11 @@ static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
> >       {}
> >  };
> >

> > +struct i2c_acpi_irq_context {
> > +     int irq;
> > +     int wake_capable;
>
> Why not bool?
>
SGTM


> Also perhaps 'wakeable'?
>

I kept it as wake_capable since I want to keep some consistency with
the ACPI nodes.

> > +};
> > +
> >  static int i2c_acpi_do_lookup(struct acpi_device *adev,
> >                             struct i2c_acpi_lookup *lookup)
> >  {
> > @@ -170,11 +175,14 @@ static int i2c_acpi_do_lookup(struct acpi_device *adev,
> >
> >  static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
> >  {
> > -     int *irq = data;
> > +     struct i2c_acpi_irq_context *irq_ctx = data;
> >       struct resource r;
> >
> > -     if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r))
> > -             *irq = i2c_dev_irq_from_resources(&r, 1);
> > +     if (irq_ctx->irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r)) {
> > +             irq_ctx->irq = i2c_dev_irq_from_resources(&r, 1);
> > +             irq_ctx->wake_capable =
> > +                     r.flags & IORESOURCE_IRQ_WAKECAPABLE ? 1 : 0;
>
> Then you can just do this:
>
>                 irq_ctx->wakeable = r.flags & IORESOURCE_IRQ_WAKECAPABLE;
>
> > +     }
> >
> >       return 1; /* No need to add resource to the list */
> >  }
> > @@ -182,31 +190,42 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
> >  /**
> >   * i2c_acpi_get_irq - get device IRQ number from ACPI
> >   * @client: Pointer to the I2C client device
> > + * @wake_capable: Set to 1 if the IRQ is wake capable
> >   *
> >   * Find the IRQ number used by a specific client device.
> >   *
> >   * Return: The IRQ number or an error code.
> >   */
> > -int i2c_acpi_get_irq(struct i2c_client *client)
> > +int i2c_acpi_get_irq(struct i2c_client *client, int *wake_capable)
>
> bool here too
>
> >  {
> >       struct acpi_device *adev = ACPI_COMPANION(&client->dev);
> >       struct list_head resource_list;
> > -     int irq = -ENOENT;
> > +     struct i2c_acpi_irq_context irq_ctx = {
> > +             .irq = -ENOENT,
> > +             .wake_capable = 0,
> > +     };
> >       int ret;
> >
> >       INIT_LIST_HEAD(&resource_list);
> >
> > +     if (wake_capable)
> > +             *wake_capable = 0;
>
> I think it is better to touch this only after the function succeeds so..
>
> > +
> >       ret = acpi_dev_get_resources(adev, &resource_list,
> > -                                  i2c_acpi_add_resource, &irq);
> > +                                  i2c_acpi_add_resource, &irq_ctx);
> >       if (ret < 0)
> >               return ret;
> >
> >       acpi_dev_free_resource_list(&resource_list);
> >
> > -     if (irq == -ENOENT)
> > -             irq = acpi_dev_gpio_irq_get(adev, 0);
> > +     if (irq_ctx.irq == -ENOENT)
> > +             irq_ctx.irq = acpi_dev_gpio_irq_get_wake(
> > +                     adev, 0, &irq_ctx.wake_capable);
> > +
> > +     if (wake_capable)
> > +             *wake_capable = irq_ctx.wake_capable;
>
> ... here only.
>
> >
> > -     return irq;
> > +     return irq_ctx.irq;
> >  }
> >
> >  static int i2c_acpi_get_info(struct acpi_device *adev,
> > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> > index 91007558bcb260..97315b41550213 100644
> > --- a/drivers/i2c/i2c-core-base.c
> > +++ b/drivers/i2c/i2c-core-base.c
> > @@ -468,6 +468,7 @@ static int i2c_device_probe(struct device *dev)
> >       struct i2c_client       *client = i2c_verify_client(dev);
> >       struct i2c_driver       *driver;
> >       int status;
> > +     int acpi_wake_capable = 0;
>
> You can declare this in the below block instead.
>
> >
> >       if (!client)
> >               return 0;
> > @@ -487,7 +488,10 @@ static int i2c_device_probe(struct device *dev)
> >                       if (irq == -EINVAL || irq == -ENODATA)
> >                               irq = of_irq_get(dev->of_node, 0);
> >               } else if (ACPI_COMPANION(dev)) {
>
>                         bool wakeable;
>
> > -                     irq = i2c_acpi_get_irq(client);
> > +                     irq = i2c_acpi_get_irq(client, &acpi_wake_capable);
> > +
>                         if (irq > 0 && wakeable)
>                                 client->flags |= I2C_CLIENT_WAKE;
> >               }
> >               if (irq == -EPROBE_DEFER) {
> >                       status = irq;
> > diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
> > index 87e2c914f1c57b..8e336638a0cd2e 100644
> > --- a/drivers/i2c/i2c-core.h
> > +++ b/drivers/i2c/i2c-core.h
> > @@ -61,11 +61,11 @@ static inline int __i2c_check_suspended(struct i2c_adapter *adap)
> >  #ifdef CONFIG_ACPI
> >  void i2c_acpi_register_devices(struct i2c_adapter *adap);
> >
> > -int i2c_acpi_get_irq(struct i2c_client *client);
> > +int i2c_acpi_get_irq(struct i2c_client *client, int *wake_capable);
> >  #else /* CONFIG_ACPI */
> >  static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
> >
> > -static inline int i2c_acpi_get_irq(struct i2c_client *client)
> > +static inline int i2c_acpi_get_irq(struct i2c_client *client, int *wake_capable)
> >  {
> >       return 0;
> >  }
> > --
> > 2.37.2.789.g6183377224-goog

I'll push out another patch series with all the latest changes.

Thanks for the reviews everyone.