Messages in this thread |  | | | From | Kumar Gala <> | | Subject | Re: [PATCH] IPIC: Don't call set_irq_handler with desc->lock held. | | Date | Wed, 25 Oct 2006 00:41:31 -0500 |
On Oct 23, 2006, at 11:35 AM, Scott Wood wrote:
> This patch causes ipic_set_irq_type to set the handler directly rather > than call set_irq_handler, which causes spinlock recursion because > the lock is already held when ipic_set_irq_type is called. > > I'm also not convinced that ipic_set_irq_type should be changing the > handler at all. There seem to be several controllers that don't and > several that do. Those that do would break what appears to be a > common > usage of calling set_irq_chip_and_handler followed by set_irq_type, > if a > non-standard handler were to be used. OTOH, irq_create_of_mapping() > doesn't set the handler, but only calls set_irq_type(). > > This patch gets things working in the spinlock-debugging-enabled case, > but I'm curious as to where the handler setting is ideally supposed > to be > done. I don't see any documentation on set_irq_type() that clarifies > what the semantics are supposed to be.
Guys, Scott pointed this problem out on a PPC interrupt controller, and wanted to raise it in a larger forum since it appears to exist on at least one ARM interrupt controller I looked at (ixp4xx). What is the proper solution to handle this.
The callers of set_type() I found all grab desc->lock.
- kumar
> > Signed-off-by: Scott Wood <scottwood@freescale.com> > --- > arch/powerpc/sysdev/ipic.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c > index bc4d4a7..746f78c 100644 > --- a/arch/powerpc/sysdev/ipic.c > +++ b/arch/powerpc/sysdev/ipic.c > @@ -473,9 +473,9 @@ static int ipic_set_irq_type(unsigned in > desc->status |= flow_type & IRQ_TYPE_SENSE_MASK; > if (flow_type & IRQ_TYPE_LEVEL_LOW) { > desc->status |= IRQ_LEVEL; > - set_irq_handler(virq, handle_level_irq); > + desc->handle_irq = handle_level_irq; > } else { > - set_irq_handler(virq, handle_edge_irq); > + desc->handle_irq = handle_edge_irq; > } > > /* only EXT IRQ senses are programmable on ipic > -- > 1.4.2.3 > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-dev
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