Hi,
Rafael J. Wysocki wrote:
On Friday, 11 of April 2008, Zhao Yakui wrote:
On Thu, 2008-04-10 at 23:33 +0200, matthieu castet wrote:
Hi,
this patch add a check that the memory allocated for s3 wakeup is in the
first 1MB as required by acpi spec.
Have you found whether some systems are afflicted by this ?
In fact that OS allacates the acpi_wake_address follows the below two
functions:
reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);
reserve_bootmem(PAGE_SIZE, PAGE_SIZE, BOOTMEM_DEFAULT);
That's on 32 bits kernel. Aren't the 1MB limitation valid on 64 bits
kernel ?
The above mechanism can insure that the acpi_wake_address is in memroy
below 1M. (It is unncessary to apply the patch. IMO)
Agreed.
Of course the addressing check will be more strict after this patch is
applied.
Matthieu, can you please explain why you consider the patch as necessary?
This can help to debug strange S3 wakeup problem. It make sure the
allocation is correct.
Also I believe relying on the bootmem allocator internal to be sure it
is in the first 1MB is a bad things (why can't it start allocating
memory to the top of 16MB memory).
If you are sure of the allocated memory before the call, why don't do a
reserve_bootmem(PAGE_SIZE*2, PAGE_SIZE*2, BOOTMEM_DEFAULT); ?
Matthieu
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