Re: [PATCH AUTOSEL 5.17 42/43] Revert "ACPI: Pass the same capabilities to the _OSC regardless of the query flag"

[Tom Crossland]

Hi, I'm observing the issue described here which I think is due to a 
recent regression:

https://github.com/intel/linux-intel-lts/issues/22

sudo dmesg -t -l err

ACPI BIOS Error (bug): Could not resolve symbol [\_PR.PR00._CPC], 
AE_NOT_FOUND (20211217/psargs-330)
ACPI Error: Aborting method \_PR.PR01._CPC due to previous error 
(AE_NOT_FOUND) (20211217/psparse-529)
ACPI BIOS Error (bug): Could not resolve symbol [\_PR.PR00._CPC], 
AE_NOT_FOUND (20211217/psargs-330)
ACPI Error: Aborting method \_PR.PR02._CPC due to previous error 
(AE_NOT_FOUND) (20211217/psparse-529)
ACPI BIOS Error (bug): Could not resolve symbol [\_PR.PR00._CPC], 
AE_NOT_FOUND (20211217/psargs-330)
ACPI Error: Aborting method \_PR.PR03._CPC due to previous error 
(AE_NOT_FOUND) (20211217/psparse-529)

System:
  Kernel: 5.18.9-arch1-1 arch: x86_64 bits: 64 compiler: gcc v: 12.1.0
    parameters: initrd=\intel-ucode.img initrd=\initramfs-linux.img
    root=xxx intel_iommu=on iommu=pt
 Machine:
  Type: Desktop Mobo: Intel model: NUC7i5BNB v: J31144-304 serial: <filter>
    UEFI: Intel v: BNKBL357.86A.0088.2022.0125.1102 date: 01/25/2022

I hope this is the correct forum to report the issue. Apologies if not.

On 28/03/2022 13.18, Sasha Levin wrote:
> From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
>
> [ Upstream commit 2ca8e6285250c07a2e5a22ecbfd59b5a4ef73484 ]
>
> Revert commit 159d8c274fd9 ("ACPI: Pass the same capabilities to the
> _OSC regardless of the query flag") which caused legitimate usage
> scenarios (when the platform firmware does not want the OS to control
> certain platform features controlled by the system bus scope _OSC) to
> break and was misguided by some misleading language in the _OSC
> definition in the ACPI specification (in particular, Section 6.2.11.1.3
> "Sequence of _OSC Calls" that contradicts other perts of the _OSC
> definition).
>
> Link: https://lore.kernel.org/linux-acpi/CAJZ5v0iStA0JmO0H3z+VgQsVuQONVjKPpw0F5HKfiq=Gb6B5yw@xxxxxxxxxxxxxx
> Reported-by: Mario Limonciello <Mario.Limonciello@xxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Tested-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Acked-by: Huang Rui <ray.huang@xxxxxxx>
> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
>   drivers/acpi/bus.c | 27 +++++++++++++++++++--------
>   1 file changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 07f604832fd6..079b952ab59f 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -332,21 +332,32 @@ static void acpi_bus_osc_negotiate_platform_control(void)
>   	if (ACPI_FAILURE(acpi_run_osc(handle, &context)))
>   		return;
>   
> -	kfree(context.ret.pointer);
> +	capbuf_ret = context.ret.pointer;
> +	if (context.ret.length <= OSC_SUPPORT_DWORD) {
> +		kfree(context.ret.pointer);
> +		return;
> +	}
>   
> -	/* Now run _OSC again with query flag clear */
> +	/*
> +	 * Now run _OSC again with query flag clear and with the caps
> +	 * supported by both the OS and the platform.
> +	 */
>   	capbuf[OSC_QUERY_DWORD] = 0;
> +	capbuf[OSC_SUPPORT_DWORD] = capbuf_ret[OSC_SUPPORT_DWORD];
> +	kfree(context.ret.pointer);
>   
>   	if (ACPI_FAILURE(acpi_run_osc(handle, &context)))
>   		return;
>   
>   	capbuf_ret = context.ret.pointer;
> -	osc_sb_apei_support_acked =
> -		capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
> -	osc_pc_lpi_support_confirmed =
> -		capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
> -	osc_sb_native_usb4_support_confirmed =
> -		capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_NATIVE_USB4_SUPPORT;
> +	if (context.ret.length > OSC_SUPPORT_DWORD) {
> +		osc_sb_apei_support_acked =
> +			capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
> +		osc_pc_lpi_support_confirmed =
> +			capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
> +		osc_sb_native_usb4_support_confirmed =
> +			capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_NATIVE_USB4_SUPPORT;
> +	}
>   
>   	kfree(context.ret.pointer);
>   }