[Letux-kernel] SMP issue between LX16 and LX20 found...

[H. Nikolaus Schaller]

Hm. It is strange.

Kernel letux-6.15.2 boots more reliable. After adding the serial aliases I can also get
to the login:

But: reliable only on the v0.2 board and one v0.3 board. The other two have
spurious and random virtual paging issues which do a kernel panic with auto-reboot.
Or the kernel simply gets stuck.

So I currently see a mix of three intermixed issues:
a) two lx20 boards not booting reliably
b) letux-6.16-rc1 less reliable than letux-6.15.2
c) non-SMP compiled kernel works everywhere

Maybe the dual-edge IRQ symptom also plays a role since IRQs
are used everywhere (but dual-edge only for the WKUP gpio-key)...

Looks as if I should fix that and the other issues (second µSD, USB)
first. On a kernel w/o SMP...

And I should remove CONFIG_SMP=y from the mips-generic letux_defconfig again
(since it can easily be enabled for further debugging of the SMP issue).

BR,
Nikolaus

PS: I looked into /proc/interrupts and it appears as if
the IRQs are sometimes assigned to a CPU (ttyS2, mmc0) and
sometimes not (mailbox, OST):

root at letux:~# cat /proc/interrupts 
           CPU0       CPU1       
  2:       4177          0     MIPS   2  SoC intc cascade interrupt
  3:       1923       3490     MIPS   3  core mailbox
  4:     113075       3308     MIPS   4  OST event timer
  8:          0          0      TCU   0  TCU0
  9:          0          0      TCU   1  TCU1
 10:          0          0     INTC   3  13420000.dma-controller
 31:          1          0 GPIOE  31  WAKEUP
 32:          0          0     INTC  32  10003000.rtc
 45:        594          0     INTC  45  ttyS2
 48:       3584          0     INTC  48  mmc0
ERR:          0
root at letux:~# 

with kernel w/o SMP (note that there is no core mailbox!)

root at letux:~# cat /proc/interrupts 
           CPU0       
  2:       3781     MIPS   2  SoC intc cascade interrupt
  4:      26073     MIPS   4  OST event timer
  8:          0      TCU   0  TCU0
  9:          0     INTC   3  13420000.dma-controller
 31:          1 GPIOE  31  WAKEUP
 32:          0     INTC  32  10003000.rtc
 45:        406     INTC  45  ttyS2
 48:       3374     INTC  48  mmc0
ERR:          1
root at letux:~#