Re: [PATCH v6] ACPI: skip IRQ override on AMD Zen platforms

From: Rafael J. Wysocki
Date: Thu Jul 14 2022 - 14:35:57 EST


On Tue, Jul 12, 2022 at 4:01 AM Chuanhong Guo <gch981213@xxxxxxxxx> wrote:
>
> IRQ override isn't needed on modern AMD Zen systems.
> There's an active low keyboard IRQ on AMD Ryzen 6000 and it will stay
> this way on newer platforms. This IRQ override breaks keyboards for
> almost all Ryzen 6000 laptops currently on the market.
>
> Skip this IRQ override for all AMD Zen platforms because this IRQ
> override is supposed to be a workaround for buggy ACPI DSDT and we can't
> have a long list of all future AMD CPUs/Laptops in the kernel code.
> If a device with buggy ACPI DSDT shows up, a separated list containing
> just them should be created.
>
> Suggested-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Signed-off-by: Chuanhong Guo <gch981213@xxxxxxxxx>

I need an ACK from Mario here.

> ---
> Change sice v5: reworked
>
> drivers/acpi/resource.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index c2d494784425..510cdec375c4 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -416,6 +416,16 @@ static bool acpi_dev_irq_override(u32 gsi, u8 triggering, u8 polarity,
> {
> int i;
>
> +#ifdef CONFIG_X86
> + /*
> + * IRQ override isn't needed on modern AMD Zen systems and
> + * this override breaks active low IRQs on AMD Ryzen 6000 and
> + * newer systems. Skip it.
> + */
> + if (boot_cpu_has(X86_FEATURE_ZEN))
> + return false;
> +#endif
> +
> for (i = 0; i < ARRAY_SIZE(skip_override_table); i++) {
> const struct irq_override_cmp *entry = &skip_override_table[i];
>
> --
> 2.36.1
>