Re: Help getting IP30/Octane fixed?

[Kumba <kumba@gentoo.org>]

Johannes Dickgreber wrote:

> This is whats wrong with SMP: from file include/asm/mach-ip30/heart.h
> 
> #define HEART_IMR(x)		((volatile ulong *)0x900000000ff10000 + (8 * (x)))
> 
> I schould be
> 
> #define HEART_IMR(x)		((volatile ulong *)0x900000000ff10000 + (x))
> 
> or it schould be
> 
> #define HEART_IMR(x)		((volatile ulong *) (0x900000000ff10000 + (8 * (x))))
> 
> The IRQ MASK Register for the different CPUs are side by side.
> In your version the factor 8 is used twice. First explicit inside the braces
> and second, because of the pointer to ulong implicit done by the
> compiler.
> I checked it by dissambling the code and my smp-kernel is working if i start
> only with one cpu. With 2 cpus the smp-kernel is booting, but the init process
> hangs then.

I'll have to test this when I get a new SMP module in.  Found a cheap R10K 
(yuck) on eBay for real cheap that'll suffice.  My R12000-300MHz refused to post 
at all (LED didn't even change to red, but the PROM would process NMI resets, 
oddly enough).

Ricardo (ricmm on IRC) explained it as this:

<ricmm> the baseline problem is that the secondary CPU's ipi irq is not 
triggering, the first one works
<ricmm> and smp_call_function() is calling an init function on both CPUs with a 
wait_for_completion flag set
<ricmm> but the second CPU will never run the function as the irq is not 
happening, therefore the flag will remain set
<ricmm> and smp_call_function() will spin waiting for the completion


> the revert is not needed anymore, because of code in arch/mips/pci/ops-bridge.c
> look for the function emulate_ioc3_cfg

Awesome, that's great to know!


> i have done some more work on the older patches and have a working kernel.
> if someone wants this patch, i can send it.

I'll take a look at it and see if I can integrate it into what I already have. 
Do you have it broken out into separate changes for the IOC3 metadriver and for 
the core IP30 code?


Thanks!

-- 
Joshua Kinard
Gentoo/MIPS
kumba@gentoo.org

"The past tempts us, the present confuses us, the future frightens us.  And our 
lives slip away, moment by moment, lost in that vast, terrible in-between."

--Emperor Turhan, Centauri Republic