[U-Boot] [PATCH v1 2/2] x86: zImage: Propagate acpi_rsdp_addr to kernel via boot parameters

[Bin Meng]

On Mon, Jun 18, 2018 at 5:22 PM, Andy Shevchenko
<andriy.shevchenko at linux.intel.com> wrote:
> On Sun, 2018-06-17 at 07:22 +0800, Bin Meng wrote:
>> Hi Andy,
>>
>> On Fri, Jan 12, 2018 at 9:01 PM, Andy Shevchenko
>> <andriy.shevchenko at linux.intel.com> wrote:
>> > On Fri, 2018-01-12 at 17:00 +0800, Bin Meng wrote:
>> > > Hi Andy,
>> > >
>> > > On Thu, Jan 11, 2018 at 1:40 AM, Andy Shevchenko
>> > > <andriy.shevchenko at linux.intel.com> wrote:
>> > > > New field acpi_rsdp_addr, which has been introduced in boot
>> > > > protocol
>> > > > v2.14 [1], in boot parameters tells kernel the exact address of
>> > > > RDSP
>> > > > ACPI table. Knowing it increases robustness of the kernel by
>> > > > avoiding
>> > > > in some cases traversal through a part of physical memory.
>> > > > It will slightly reduce boot time by the same reason.
>> > > >
>> > > > [1] See Linux kernel commit
>> > > >
>> > > >   2f74cbf947f4 ("x86/boot: Add the ACPI RSDP address to struct
>> > > > setup_header::acpi_rdsp_addr")
>> > >
>> > > I don't see this commit id in my linux tree. Is this in some
>> > > custodian's tree?
>> >
>> > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?
>> > id=2
>> > f74cbf947f45fa082dda8eac1a1f1299a372f49
>> >
>>
>> I checked Linux kernel tree, seems the patch of adding acpi_rdsp_addr
>> to setup_header was never accepted. Can you please double check, to
>> see whether we still need this in U-Boot?
>>
>> I built a v4.17 kernel, and the boot protocol is still 2.13.
>
> Indeed. There were a discussion to not apply it for now.
>

I did not find the discussion. Do we need revert the changes in U-Boot?

Regards,
Bin