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Subject: Re: asus-wmi fails to load on new ASUS laptop UX325JA
To:     Chris Chiu <chiu@endlessm.com>, Darren Hart <dvhart@infradead.org>,
        Andy Shevchenko <andy@infradead.org>,
        gregkh@linuxfoundation.org, gayatri.kammela@intel.com,
        Mika Westerberg <mika.westerberg@linux.intel.com>
Cc:     Platform Driver <platform-driver-x86@vger.kernel.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        Linux Upstreaming Team <linux@endlessm.com>
References: <CAB4CAweJ6Zi2DqQ5qgQq-apAMzSSk3uzoohEJ443F5T=LohAAA@mail.gmail.com>
From:   Hans de Goede <hdegoede@redhat.com>
Message-ID: <6c8e947e-ebd4-f63f-db17-fabd2082ae66@redhat.com>
Date:   Thu, 21 May 2020 16:30:11 +0200
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Hi,

On 5/21/20 12:33 PM, Chris Chiu wrote:
> Hi,
>      I have the ASUS new laptop UX325JA and most of the media keys are
> not working even with the latest kernel (5.7.0-rc5+). Looking into the
> dmesg log, the ASUS WMI driver fails to load because of
> [    7.827241] asus-nb-wmi: probe of asus-nb-wmi failed with error -5.
> 
>      Before this message, the following message repeat 5 times, please
> check the full dmesg log here
> https://gist.github.com/mschiu77/9a53cd8ff17029e949210dfb3ec1213f
> [    7.825975] ACPI BIOS Error (bug): AE_AML_BUFFER_LIMIT, Field
> [IIA3] at bit offset/length 96/32 exceeds size of target Buffer (96
> bits) (20200326/dsopcode-203)
> [    7.825985] No Local Variables are initialized for Method [WMNB]
> [    7.826005] ACPI Error: Aborting method \_SB.ATKD.WMNB due to
> previous error (AE_AML_BUFFER_LIMIT) (20200326/psparse-531)
> 
>      It fails the \_SB.ATKD.WMNB because the local variable IIA3
> exceeds the buffer limit. The WMNB is the function to deal with all
> ASUS WMI functions, such as ASUS_WMI_METHODID_INIT...etc. The related
> code in DSDT is as follows. The full DSDT is here
> https://gist.github.com/mschiu77/849c6cb89a8d8cadd015fa75465882dd
> 
> Method (WMNB, 3, Serialized)
> {
>      P8XH (Zero, 0x11)
>      CreateDWordField (Arg2, Zero, IIA0)
>      CreateDWordField (Arg2, 0x04, IIA1)
>      CreateDWordField (Arg2, 0x08, IIA2)
>      CreateDWordField (Arg2, 0x0C, IIA3)
>      CreateDWordField (Arg2, 0x10, IIA4)
>      Local0 = (Arg1 & 0xFFFFFFFF)
>      If ((Local0 == 0x54494E49))
> 
>      Just as the error messages indicated,  the IIA3 is out of boundary
> for the target Buffer. The limit 96bits (12 bytes) is determined by
> the input acpi_buffer size, which refers to internally defined struct
> bios_args, in asus_wmi_evaluate_method3. Because all ASUS WMI
> evaluations will invoke  asus_wmi_evaluate_method3 at last, so all
> ASUS WMI functions fail to work. I can simply fix this by extending
> the bios_args from 3 args to 5 u32 args as follows, but I don't think
> it's generic enough and may have to change if there're more local
> variables declared in ACPI method on the future ASUS machines. Any
> suggestions for this?

I think you fix with just adding the 2 extra args is fine. Yes we
may need to extend this in the future. But we have no idea when and
with how many extra args. So for now I believe we should just move
forward with your suggested fix.

If you can turn this into a proper patch and submit it upstream
that would be great.

Regards,

Hans


> 
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -116,6 +116,8 @@ struct bios_args {
>          u32 arg0;
>          u32 arg1;
>          u32 arg2; /* At least TUF Gaming series uses 3 dword input buffer. */
> +       u32 arg3;
> +       u32 arg4;
>   } __packed;
> 
> 
> Chris
>