On 2014/11/14 23:31, Marc Zyngier wrote: > On 12/11/14 13:43, Thomas Gleixner wrote: >> From: Jiang Liu <[email protected]> >> >> Signed-off-by: Jiang Liu <[email protected]> >> Cc: Bjorn Helgaas <[email protected]> >> Cc: Grant Likely <[email protected]> >> Cc: Marc Zyngier <[email protected]> >> Cc: Yingjoe Chen <[email protected]> >> Cc: Yijing Wang <[email protected]> >> Signed-off-by: Thomas Gleixner <[email protected]> >> --- >> include/linux/irqdomain.h | 5 +++++ >> kernel/irq/irqdomain.c | 10 ++++++++++ >> 2 files changed, 15 insertions(+) >> >> Index: tip/include/linux/irqdomain.h >> =================================================================== >> --- tip.orig/include/linux/irqdomain.h >> +++ tip/include/linux/irqdomain.h >> @@ -33,6 +33,7 @@ >> #define _LINUX_IRQDOMAIN_H >> >> #include <linux/types.h> >> +#include <linux/irqhandler.h> >> #include <linux/radix-tree.h> >> >> struct device_node; >> @@ -263,6 +264,10 @@ extern int irq_domain_set_hwirq_and_chip >> irq_hw_number_t hwirq, >> struct irq_chip *chip, >> void *chip_data); >> +extern void irq_domain_set_info(struct irq_domain *domain, unsigned int >> virq, >> + irq_hw_number_t hwirq, struct irq_chip *chip, >> + void *chip_data, irq_flow_handler_t handler, >> + void *handler_data, const char *handler_name); >> extern void irq_domain_reset_irq_data(struct irq_data *irq_data); >> extern void irq_domain_free_irqs_common(struct irq_domain *domain, >> int virq, int nr_irqs); >> Index: tip/kernel/irq/irqdomain.c >> =================================================================== >> --- tip.orig/kernel/irq/irqdomain.c >> +++ tip/kernel/irq/irqdomain.c >> @@ -882,6 +882,16 @@ int irq_domain_set_hwirq_and_chip(struct >> return 0; >> } >> >> +void irq_domain_set_info(struct irq_domain *domain, unsigned int virq, >> + irq_hw_number_t hwirq, struct irq_chip *chip, >> + void *chip_data, irq_flow_handler_t handler, >> + void *handler_data, const char *handler_name) >> +{ >> + irq_domain_set_hwirq_and_chip(domain, virq, hwirq, chip, chip_data); >> + __irq_set_handler(virq, handler, 0, handler_name); >> + irq_set_handler_data(virq, handler_data); >> +} >> + > > We still have the issue that, depending on where in the stack this is > called, this will succeed or fail: If this is called from the inner > irqchip, __irq_set_handler() will fail, as it will look at the outer > domain as the (desc->irq_data.chip == &no_irq_chip) test fails (we > haven't set the top level yet). > > I have this very imperfect workaround in my tree: > > diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c > index d028b34..91e6515 100644 > --- a/kernel/irq/chip.c > +++ b/kernel/irq/chip.c > @@ -731,7 +731,16 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t > handle, int is_chained, > if (!handle) { > handle = handle_bad_irq; > } else { > - if (WARN_ON(desc->irq_data.chip == &no_irq_chip)) > +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY > + struct irq_data *irq_data = &desc->irq_data; > + while (irq_data) { > + if (irq_data->chip != &no_irq_chip) > + break; > + irq_data = irq_data->parent_data; > + } > +#endif > + > + if (WARN_ON(!irq_data || irq_data->chip == &no_irq_chip)) > goto out; > } > > Which translate into: If there is at least one irqchip in the domain, > it will probably sort itself out. Not ideal. Any real solution to > this problem? > > GICv2 faces this exact problem, as some of its interrupts are used > directly, and some others are used through the MSI domain. In the > GIC driver, it is almost impossible to find out... Hi Marc, I prefer the above solution to relax the warning conditions. Changing the calling order in irq_domain_ops->alloc() looks a little strange, and other interrupt drivers may still run into the same issue. Regards! Gerry
> > Thanks, > > M. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
