lkml.org 
[lkml]   [2018]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH] powerpc/mpic: Cleanup irq vector accounting
Date


> -----Original Message-----
> From: Michael Ellerman [mailto:mpe@ellerman.id.au]
> Sent: Wednesday, July 4, 2018 6:57 PM
> To: Bharat Bhushan <bharat.bhushan@nxp.com>;
> benh@kernel.crashing.org; paulus@samba.org; robh@kernel.org;
> geoff@infradead.org; tyreld@linux.vnet.ibm.com; linuxppc-
> dev@lists.ozlabs.org; linux-kernel@vger.kernel.org
> Cc: Bharat Bhushan <bharat.bhushan@nxp.com>
> Subject: Re: [PATCH] powerpc/mpic: Cleanup irq vector accounting
>
> Bharat Bhushan <Bharat.Bhushan@nxp.com> writes:
>
> > Available vector space accounts ipis and timer interrupts while
> > spurious vector was not accounted.
>
> OK. What is the symptom of that? Nothing? Total system crash?
>
> Looks like this can be tagged:
>
> Fixes: 0a4081641d72 ("powerpc/mpic: FSL MPIC error interrupt support.")
>
> Which added the code that uses "12".
>
> > Also later
> > mpic_setup_error_int() escape one more vector, seemingly it assumes
> > one spurious vector.
>
> Ah right, I get it now.
>
> So there is no bug. It's just a disagreement about whether the "intvec"
> argument to mpic_setup_error_int() indicates the first number that's free to
> use or the last number that has been allocated.
>
> Right?

Yes, it is not any bug fix. This is minor cleanup where passing rather than passing "last intvec used" to "intvec to be used" in mpic_setup_error_int().

Thanks
-Bharat

>
> cheers
>
> > Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
> > ---
> > arch/powerpc/sysdev/fsl_mpic_err.c | 2 +-
> > arch/powerpc/sysdev/mpic.c | 6 +++---
> > 2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/powerpc/sysdev/fsl_mpic_err.c
> > b/arch/powerpc/sysdev/fsl_mpic_err.c
> > index 488ec45..2a98837 100644
> > --- a/arch/powerpc/sysdev/fsl_mpic_err.c
> > +++ b/arch/powerpc/sysdev/fsl_mpic_err.c
> > @@ -76,7 +76,7 @@ int mpic_setup_error_int(struct mpic *mpic, int
> intvec)
> > mpic->flags |= MPIC_FSL_HAS_EIMR;
> > /* allocate interrupt vectors for error interrupts */
> > for (i = MPIC_MAX_ERR - 1; i >= 0; i--)
> > - mpic->err_int_vecs[i] = --intvec;
> > + mpic->err_int_vecs[i] = intvec--;
> >
> > return 0;
> > }
> > diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
> > index 1d4e0ef6..e098d1e 100644
> > --- a/arch/powerpc/sysdev/mpic.c
> > +++ b/arch/powerpc/sysdev/mpic.c
> > @@ -1380,12 +1380,12 @@ struct mpic * __init mpic_alloc(struct
> device_node *node,
> > * global vector number space, as in case of ipis
> > * and timer interrupts.
> > *
> > - * Available vector space = intvec_top - 12, where 12
> > + * Available vector space = intvec_top - 13, where 13
> > * is the number of vectors which have been consumed by
> > - * ipis and timer interrupts.
> > + * ipis, timer interrupts and spurious.
> > */
> > if (fsl_version >= 0x401) {
> > - ret = mpic_setup_error_int(mpic, intvec_top - 12);
> > + ret = mpic_setup_error_int(mpic, intvec_top - 13);
> > if (ret)
> > return NULL;
> > }
> > --
> > 1.9.3

\
 
 \ /
  Last update: 2018-07-05 17:43    [W:0.146 / U:2.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site