Boot regression in 4.8 for Mac Pro server

Boot regression in 4.8 for Mac Pro server

[Scott Talbert]

Hi,

I just recently discovered a boot regression that occurred starting in 4.8 
on a Mac Pro Mid-2012 server (MacPro5,1).  Yes, I realize this problem is 
over 3 years old.  Obviously, I haven't been using Linux on this hardware 
in a while.  :-)  I bisected the regression to 
475fb4e8b2f4444d1d7b406ff3a7d21bc89a1e6f "efi / ACPI: load SSTDs from EFI 
variables".  And indeed, v5.3-rc7 will boot if I comment out the 
efivar_ssdt_load() call, as in:

$ git diff
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index ad3b1f4866b3..691a8671a2ba 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -364,8 +364,8 @@ static int __init efisubsys_init(void)
         if (error)
                 goto err_put;

-       if (efi_enabled(EFI_RUNTIME_SERVICES))
-               efivar_ssdt_load();
+       //if (efi_enabled(EFI_RUNTIME_SERVICES))
+       //      efivar_ssdt_load();

         error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
         if (error) {


Any thoughts on how to fix this?

Thanks,
Scott

Re: Boot regression in 4.8 for Mac Pro server

[Ard Biesheuvel]

On Wed, 11 Sep 2019 at 21:48, Scott Talbert <swt@techie.net> wrote:
>
> Hi,
>
> I just recently discovered a boot regression that occurred starting in 4.8
> on a Mac Pro Mid-2012 server (MacPro5,1).  Yes, I realize this problem is
> over 3 years old.  Obviously, I haven't been using Linux on this hardware
> in a while.  :-)  I bisected the regression to
> 475fb4e8b2f4444d1d7b406ff3a7d21bc89a1e6f "efi / ACPI: load SSTDs from EFI
> variables".  And indeed, v5.3-rc7 will boot if I comment out the
> efivar_ssdt_load() call, as in:
>
> $ git diff
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index ad3b1f4866b3..691a8671a2ba 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -364,8 +364,8 @@ static int __init efisubsys_init(void)
>          if (error)
>                  goto err_put;
>
> -       if (efi_enabled(EFI_RUNTIME_SERVICES))
> -               efivar_ssdt_load();
> +       //if (efi_enabled(EFI_RUNTIME_SERVICES))
> +       //      efivar_ssdt_load();
>
>          error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
>          if (error) {
>
>
> Any thoughts on how to fix this?
>

Thanks for the report. It appears the SSDT loading code is slightly
broken, in the sense that it always iterates over all EFI variables
regardless of whether an SSDT override was actually requested on the
command line, which is silly.

I'll have a patch out shortly, and I'll put you on cc. Please test it
and report back.