Dear Paul, Am Dienstag, 21. August 2018, 01:31:11 CEST schrieb Paul Burton: [...] > > 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. Here is the boot log without the patch [ 0.000000] SoC Type: Ralink RT2880 id:2 rev:1 [...] [ 0.000000] CPU0 revision is: 0001906c (MIPS 4KEc) [ 0.000000] MIPS: machine is Belkin F5D8235 v1 [ 0.000000] Determined physical RAM map: [ 0.000000] memory: 02000000 @ 08000000 (usable) [ 0.000000] Wasting 1048576 bytes for tracking 32768 unused pages [...] [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000000000000-0x0000000009ffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x0000000009ffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000009ffffff] [...] [ 0.000000] Memory: 23712K/163840K available (3334K kernel code, 162K rwdata, 808K rodata, 2984K init, 208K bss, 140128K reserved, 0K cma-reserved) [...] [ 0.000000] NR_IRQS: 256 [ 0.000000] Failed to request intc memory [ 0.000000] Kernel panic - not syncing: Failed to request resources for ralink,rt2880-sysc [ 0.000000] Rebooting in 1 seconds.. [ 0.000000] Reboot failed -- System halted ... and here with ... [ 0.000000] SoC Type: Ralink RT2880 id:2 rev:1 [...] [ 0.000000] CPU0 revision is: 0001906c (MIPS 4KEc) [ 0.000000] MIPS: machine is Belkin F5D8235 v1 [ 0.000000] Determined physical RAM map: [ 0.000000] memory: 02000000 @ 08000000 (usable) [ 0.000000] Wasting 1048576 bytes for tracking 32768 unused pages [ 0.000000] Initrd not found or empty - disabling initrd [...] [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000008000000-0x0000000009ffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000008000000-0x0000000009ffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000008000000-0x0000000009ffffff] [...] [ 0.000000] Memory: 26700K/32768K available (3334K kernel code, 162K rwdata, 808K rodata, 1192K init, 208K bss, 6068K reserved, 0K cma-reserved) [...] [ 0.000000] NR_IRQS: 256 [ 0.000000] CPU Clock: 266MHz The command line does not contain any custom "mem=" entries, that's why the patch checks "usermem". Please be aware that the platform already has a memory related issue I tried to fix with another patch "mm: Fix alloc_node_mem_map with ARCH_PFN_OFFSET calculation" [1]. So you might be right that this is not the root cause for both issues. I guess the patch might be useful anyway as it originated from the "early_parse_mem" function and memory was not reserved for non usermem setups anyway. Currently I'm testing this device with an OpenWRT based image and compiled a vanilla kernel separately to validate that this is not triggered outside the mainline one. Best regards Tobias [1] https://patchwork.linux-mips.org/patch/14627/
