Re: [PATCH 06/15] irqdomain: Ensure type settings match for an existing mapping

[Grygorii Strashko]

On 03/17/2016 08:18 PM, Jon Hunter wrote:
> On 17/03/16 14:19, Jon Hunter wrote:
> > When mapping an IRQ, if a mapping already exists, then we simply return
> > the virtual IRQ number. However, we do not check that the type settings
> > for the existing mapping match those for the mapping that is about to be
> > created. It may be unlikely that the type settings would not match, but
> > check for this and don't return a valid IRQ mapping if the type settings
> > do not match.
> >
> > WARN if the type return by irq_domain_translate() has bits outside the
> > sense mask set and then clear these bits. If these bits are not cleared
> > then this will cause the comparision of the type settings for an
> > existing mapping to fail with that of the new mapping even if the sense
> > bit themselves match. The reason being is that the existing type
> > settings are read by calling irq_get_trigger_type() which will clear
> > any bits outside the sense mask. This will allow us to detect irqchips
> > that are not correctly clearing these bits and fix them.
> >
> > Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> > ---
> >   kernel/irq/irqdomain.c | 59 ++++++++++++++++++++++++++++++++++++--------------
> >   1 file changed, 43 insertions(+), 16 deletions(-)
> >
> > diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> > index 3a519a01118b..0ea285baa619 100644
> > --- a/kernel/irq/irqdomain.c
> > +++ b/kernel/irq/irqdomain.c
> > @@ -549,6 +549,13 @@ static int irq_domain_translate(struct irq_domain *d,
> >   				     fwspec->param, fwspec->param_count,
> >   				     hwirq, type);


> > +	/*
> > +	 * WARN if the irqchip returns a type with bits
> > +	 * outside the sense mask set and clear these bits.
> > +	 */
> > +	if (WARN_ON(*type & ~IRQ_TYPE_SENSE_MASK))
> > +		*type &= IRQ_TYPE_SENSE_MASK;

Not sure that this warn and in this place make sense.
type will come unchanged here from caller irq_create_fwspec_mapping()



[...]


--
regards,
-grygorii