linux-kernel - Re: [REGRESSION] Failure to write the NVRAM variables starting from kernel 6.0 on T2 Macs

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Date:   Wed, 26 Oct 2022 21:18:06 +0000
From:   Aditya Garg <gargaditya08@...e.com>
To:     Ard Biesheuvel <ardb@...nel.org>
CC:     "matthew.garrett@...ula.com" <matthew.garrett@...ula.com>,
        "jk@...abs.org" <jk@...abs.org>,
        "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Orlando Chamberlain <redecorating@...tonmail.com>
Subject: Re: [REGRESSION] Failure to write the NVRAM variables starting from
 kernel 6.0 on T2 Macs

Hi Ard

Just a friendly reminder to get updates on the patch you asked me to test, as it seems to fix my issue.

> Thanks for the report. I did identify an issue in some refactoring
> work of the efivars layer that went into 6.0
> 
> Can you please check whether the change below fixes the issue for you?
> 
> diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
> index dd74d2ad3184..35edba93cf14 100644
> --- a/drivers/firmware/efi/vars.c
> +++ b/drivers/firmware/efi/vars.c
> @@ -209,7 +209,7 @@ efivar_set_variable_blocking(efi_char16_t *name,
> efi_guid_t *vendor,
>        if (data_size > 0) {
>                status = check_var_size(attr, data_size +
>                                              ucs2_strsize(name, 1024));
> -               if (status != EFI_SUCCESS)
> +               if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED)
>                        return status;
>        }
>        return __efivars->ops->set_variable(name, vendor, attr,
> data_size, data);
> @@ -242,7 +242,7 @@ efi_status_t
> efivar_set_variable_locked(efi_char16_t *name, efi_guid_t *vendor,
>        if (data_size > 0) {
>                status = check_var_size_nonblocking(attr, data_size +
> 
> ucs2_strsize(name, 1024));
> -               if (status != EFI_SUCCESS)
> +               if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED)
>                        return status;
>        }
>        return setvar(name, vendor, attr, data_size, data);

Regards
Aditya