Re: [PATCH] powerpc: ipic - fix status get and status clear

[Christophe LEROY]

Le 19/10/2017 Ã 07:06, Michael Ellerman a ÃcritÂ:
> Christophe Leroy <christophe.leroy@xxxxxx> writes:
>
> > IPIC Status is provided by register IPIC_SERSR and not by IPIC_SERMR
> > which is the mask register.
>
> This seems like it would be a bad bug. But I guess it hasn't mattered
> for some reason?

As far as I can see, this function has been added in kernel 2.6.12 but 
has never been used in-tree.

I have discovered this error while implementing NMI watchdog on a 832x 
board, ie this function is needed to know when a machine check exception 
is generated by the watchdog timer.

Christophe

> cheers
>
> > diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c
> > index 16f1edd78c40..535cf1f6941c 100644
> > --- a/arch/powerpc/sysdev/ipic.c
> > +++ b/arch/powerpc/sysdev/ipic.c
> > @@ -846,12 +846,12 @@ void ipic_disable_mcp(enum ipic_mcp_irq mcp_irq)
> >   
> >   u32 ipic_get_mcp_status(void)
> >   {
> > -	return ipic_read(primary_ipic->regs, IPIC_SERMR);
> > +	return ipic_read(primary_ipic->regs, IPIC_SERSR);
> >   }
> >   
> >   void ipic_clear_mcp_status(u32 mask)
> >   {
> > -	ipic_write(primary_ipic->regs, IPIC_SERMR, mask);
> > +	ipic_write(primary_ipic->regs, IPIC_SERSR, mask);
> >   }
> >   
> >   /* Return an interrupt vector or 0 if no interrupt is pending. */
> > --
> > 2.13.3