Re: [U-Boot] [PATCH v1 7/7] x86: acpi: Don't touch hardware on HW reduced platforms

Hi Andy,

On Sat, Jul 22, 2017 at 3:32 AM, Andy Shevchenko andriy.shevchenko@linux.intel.com wrote:

If ACPI HW reduced bit in FADT is set we should ignore any ACPI hardware communications.

Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com

arch/x86/lib/acpi_table.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c index da6014fb41..3eb101105b 100644 --- a/arch/x86/lib/acpi_table.c +++ b/arch/x86/lib/acpi_table.c @@ -463,6 +463,10 @@ ulong write_acpi_tables(ulong start)

    debug("ACPI: done\n");

•   /* Don't touch ACPI hardware on HW reduced platforms */
  

•   if (fadt->flags & ACPI_FADT_HW_REDUCED_ACPI)
  

•           return current;
  

Reviewed-by: Bin Meng bmeng.cn@gmail.com

I assume this is needed on Intel Edison. If that's the case, will you support S3 resume on Edison? And if yes, I believe we will need update acpi_resume() to add the same check there?

    /*
     * Other than waiting for OSPM to request us to switch to ACPI mode,
     * do it by ourselves, since SMI will not be triggered.

--

Regards, Bin