Messages in this thread | | | Date | Tue, 20 Sep 2022 15:32:13 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH v4 07/13] i2c: acpi: Use ACPI wake capability bit to set wake_irq |
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On Mon, Sep 19, 2022 at 09:59:09AM -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.
...
> + if (irq_ctx.irq == -ENOENT) > + irq_ctx.irq = acpi_dev_gpio_irq_wake_get(adev, 0, &irq_ctx.wake_capable);
I just realized, that there is an inconsistency on how we fill the wake_capable parameter. In some cases we check for IRQ for an error condition (IRQ not found) and in some the wake_capable still be filled.
Here the best approach I believe is to add
if (irq_ctx.irq < 0) return irq_ctx.irq;
I.o.w. we apply the rule "do not fill the output parameters when it's known to be an error condition".
> + if (wake_capable) > + *wake_capable = irq_ctx.wake_capable;
> + return irq_ctx.irq;
-- With Best Regards, Andy Shevchenko
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