Hi Tobias,
On Mon, Aug 20, 2018 at 01:10:38PM +0200, Tobias Wolf wrote:
Commit 67a3ba25aa95 ("MIPS: Fix incorrect mem=X@Y handling") introduced a new issue for rt288x where "PHYS_OFFSET" is 0x0 but the calculated "ramstart" is not. As the prerequisite of custom memory map has been removed, this results in the full memory range of 0x0 - 0x8000000 to be marked as reserved for this platform.
This patch adds the originally intended prerequisite again.
Could you please give an example of a typical memory layout on your platform, and what mem= arguments you're using? That would help a lot in being able to understand what's going wrong with the existing code.
Signed-off-by: Tobias Wolf dev-NTEO@vplace.de
You'd want to add at least a fixes tag here:
Fixes: 67a3ba25aa95 ("MIPS: Fix incorrect mem=X@Y handling")
And ideally add the Cc: stable tag indicating the version the fix ought to be backported to, something like:
Cc: stable@vger.kernel.org # v4.16+
As an aside, if your system generally has a non-zero ramstart perhaps it would be worth having it select MIPS_AUTO_PFN_OFFSET in Kconfig? (New in the 4.19 merge window.) That would effectively adjust PHYS_OFFSET to match ramstart, and not waste memory on struct page for the region below ramstart.
Thanks, Paul