Hi Mike,
On Tue, Mar 16, 2021 at 11:33 PM Mike Rapoport rppt@kernel.org wrote:
Hi Ilya,
On Tue, Mar 16, 2021 at 10:10:09PM -0700, Ilya Lipnitskiy wrote:
Hi Thomas,
On Fri, Mar 12, 2021 at 7:19 AM Thomas Bogendoerfer tsbogend@alpha.franken.de wrote:
On Sun, Mar 07, 2021 at 11:40:30AM -0800, Ilya Lipnitskiy wrote:
From: Tobias Wolf dev-NTEO@vplace.de
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.
and where is the problem here ?
Turns out this was already attempted to be upstreamed - not clear why it wasn't merged. Context: https://lore.kernel.org/linux-mips/6504517.U6H5IhoIOn@loki/
I hope the thread above helps you understand the problem.
The memory initialization was a bit different then. Do you still see the same problem?
Thanks for asking. I obtained a RT2880 device and gave it a try. It hangs at boot without this patch, however selecting MIPS_AUTO_PFN_OFFSET fixes it. Also, no more messages like "Wasting 1048576 bytes for tracking 32768 unused pages". MIPS_AUTO_PFN_OFFSET was suggested by Paul Burton here: https://lore.kernel.org/linux-mips/20180820233111.xww5232dxbuouf4n@pburton-l...
I will supersede this patch with one that simply selects MIPS_AUTO_PFN_OFFSET for this SOC.
Ilya