Re: Amiga, serial and SYSRQ

Michael Schmitz
2024-05-20T21:01:05Z

Paolo,

On 21/05/24 05:17, Paolo Pisati wrote:
> On Sun, May 19, 2024 at 04:58:17PM +0200, Geert Uytterhoeven wrote:
>
>> Probably some of the Warp 1260 on-board hardware has its interrupt line
>> asserted, causing an interrupt storm when Linux enables interrupts.
>> Amiboot knows how to reset several boards to prevent this, but it
>> doesn't support Warp 1260 yet.
>>
>> https://github.com/geertu/m68kboot/blob/master/common/amiga/linuxboot.c#L195
> Doesn't the kernel print out something like "too many spurious interrupts etcetc" in
> this case?
Used to do that, yes. But I haven't found that message in current mainline.
>
> Anyhow, any debug option i could turn on? I've tried everything IRQ related, but

CONFIG_CONSOLE_LOGLEVEL_DEFAULT should be high enough to print messages
of level WARN:

asmlinkage void handle_badint(struct pt_regs *regs)
{
atomic_inc(&irq_err_count);
pr_warn("unexpected interrupt from %u\n", regs->vector);
}

That would help to verify Geert's reading of the problem (which I have
no doubt is the correct one).

The interrupt vector number will tell us what interrupt level is causing
the storm (if it's an autovector int).

CONFIG_CONSOLE_LOGLEVEL_DEFAULT=7 is what I have set in my builds.

> that didn't change a bit. I understand it requires a new fw from the board
> manufacturer or a quirk in the bootloader, but i would like to get something more
> verbose before i ping them.

Interrupt level and vector number would help the manufacturer to give us
the information required to disable the problematic interrupt source.

Cheers,

Michael