Re: [PATCH v2 07/13] i2c: acpi: Use ACPI wake capability bit to set wake_irq
From: Raul Rangel
Date: Wed Sep 14 2022 - 17:00:59 EST
On Tue, Sep 13, 2022 at 11:54 PM Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxxx>
> > ---
> >
> > 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.