| Message ID | 1350425269-11489-1-git-send-email-khilman@deeprootsystems.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Oct 16, 2012 at 03:07:49PM -0700, Kevin Hilman wrote: > From: Thomas Gleixner <tglx@linutronix.de> > > Attempts to retrigger nested threaded IRQs currently fail because they > have no primary handler. In order to support retrigger of nested > IRQs, the parent IRQ needs to be retriggered. > > To fix, when an IRQ needs to be resent, if the interrupt has a parent > IRQ and runs in the context of the parent IRQ, then resend the parent. > > Also, handle_nested_irq() needs to clear the replay flag like the > other handlers, otherwise check_irq_resend() will set it and it will > never be cleared. Without clearing, it results in the first resend > working fine, but check_irq_resend() returning early on subsequent > resends because the replay flag is still set. > > Problem discovered on ARM/OMAP platforms where a nested IRQ that's > also a wakeup IRQ happens late in suspend and needed to be retriggered > during the resume process. > > Reported-by: Kevin Hilman <khilman@ti.com> > Tested-by: Kevin Hilman <khilman@ti.com> > [khilman@ti.com: changelog edits, clear IRQS_REPLAY in handle_nested_irq()] > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Umm, we also have the converse situation. We have platforms where the resend has to be done from the child IRQ, and the parent must not be touched. I hope that doesn't break those. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Russell King - ARM Linux <linux@arm.linux.org.uk> writes: > On Tue, Oct 16, 2012 at 03:07:49PM -0700, Kevin Hilman wrote: >> From: Thomas Gleixner <tglx@linutronix.de> >> >> Attempts to retrigger nested threaded IRQs currently fail because they >> have no primary handler. In order to support retrigger of nested >> IRQs, the parent IRQ needs to be retriggered. >> >> To fix, when an IRQ needs to be resent, if the interrupt has a parent >> IRQ and runs in the context of the parent IRQ, then resend the parent. >> >> Also, handle_nested_irq() needs to clear the replay flag like the >> other handlers, otherwise check_irq_resend() will set it and it will >> never be cleared. Without clearing, it results in the first resend >> working fine, but check_irq_resend() returning early on subsequent >> resends because the replay flag is still set. >> >> Problem discovered on ARM/OMAP platforms where a nested IRQ that's >> also a wakeup IRQ happens late in suspend and needed to be retriggered >> during the resume process. >> >> Reported-by: Kevin Hilman <khilman@ti.com> >> Tested-by: Kevin Hilman <khilman@ti.com> >> [khilman@ti.com: changelog edits, clear IRQS_REPLAY in handle_nested_irq()] >> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > > Umm, we also have the converse situation. We have platforms where the > resend has to be done from the child IRQ, and the parent must not be > touched. I hope that doesn't break those. I'm assuming the child IRQs you're concerned with are not threaded, right? This patch only addresses nested, threaded IRQs, and these don't have a primary handler to run at all, so cannot do any triggering. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 23 Oct 2012, Kevin Hilman wrote: > Russell King - ARM Linux <linux@arm.linux.org.uk> writes: > > > On Tue, Oct 16, 2012 at 03:07:49PM -0700, Kevin Hilman wrote: > >> From: Thomas Gleixner <tglx@linutronix.de> > >> > >> Attempts to retrigger nested threaded IRQs currently fail because they > >> have no primary handler. In order to support retrigger of nested > >> IRQs, the parent IRQ needs to be retriggered. > >> > >> To fix, when an IRQ needs to be resent, if the interrupt has a parent > >> IRQ and runs in the context of the parent IRQ, then resend the parent. > >> > >> Also, handle_nested_irq() needs to clear the replay flag like the > >> other handlers, otherwise check_irq_resend() will set it and it will > >> never be cleared. Without clearing, it results in the first resend > >> working fine, but check_irq_resend() returning early on subsequent > >> resends because the replay flag is still set. > >> > >> Problem discovered on ARM/OMAP platforms where a nested IRQ that's > >> also a wakeup IRQ happens late in suspend and needed to be retriggered > >> during the resume process. > >> > >> Reported-by: Kevin Hilman <khilman@ti.com> > >> Tested-by: Kevin Hilman <khilman@ti.com> > >> [khilman@ti.com: changelog edits, clear IRQS_REPLAY in handle_nested_irq()] > >> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > > > > Umm, we also have the converse situation. We have platforms where the > > resend has to be done from the child IRQ, and the parent must not be > > touched. I hope that doesn't break those. > > I'm assuming the child IRQs you're concerned with are not threaded, > right? This patch only addresses nested, threaded IRQs, and these don't > have a primary handler to run at all, so cannot do any triggering. And it involves that you activly set the parent irq via the new interface: irq_set_parent() You don't have that yet or you don't use that in your future changes, then you're good. :) Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/irq.h b/include/linux/irq.h index 216b0ba..526f10a 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -392,6 +392,15 @@ static inline void irq_move_masked_irq(struct irq_data *data) { } extern int no_irq_affinity; +#ifdef CONFIG_HARDIRQS_SW_RESEND +int irq_set_parent(int irq, int parent_irq); +#else +static inline int irq_set_parent(int irq, int parent_irq) +{ + return 0; +} +#endif + /* * Built-in IRQ handlers for various IRQ types, * callable via desc->handle_irq() diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 0ba014c..623325e 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -11,6 +11,8 @@ struct irq_affinity_notify; struct proc_dir_entry; struct module; +struct irq_desc; + /** * struct irq_desc - interrupt descriptor * @irq_data: per irq and chip data passed down to chip functions @@ -65,6 +67,7 @@ struct irq_desc { #ifdef CONFIG_PROC_FS struct proc_dir_entry *dir; #endif + int parent_irq; struct module *owner; const char *name; } ____cacheline_internodealigned_in_smp; diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 57d86d0..3aca9f2 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -272,6 +272,7 @@ void handle_nested_irq(unsigned int irq) raw_spin_lock_irq(&desc->lock); + desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING); kstat_incr_irqs_this_cpu(irq, desc); action = desc->action; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 4c69326..d06a396 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -616,6 +616,22 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, return ret; } +#ifdef CONFIG_HARDIRQS_SW_RESEND +int irq_set_parent(int irq, int parent_irq) +{ + unsigned long flags; + struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); + + if (!desc) + return -EINVAL; + + desc->parent_irq = parent_irq; + + irq_put_desc_unlock(desc, flags); + return 0; +} +#endif + /* * Default primary interrupt handler for threaded interrupts. Is * assigned as primary handler when request_threaded_irq is called diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index 6454db7..9065107 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -74,6 +74,14 @@ void check_irq_resend(struct irq_desc *desc, unsigned int irq) if (!desc->irq_data.chip->irq_retrigger || !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) { #ifdef CONFIG_HARDIRQS_SW_RESEND + /* + * If the interrupt has a parent irq and runs + * in the thread context of the parent irq, + * retrigger the parent. + */ + if (desc->parent_irq && + irq_settings_is_nested_thread(desc)) + irq = desc->parent_irq; /* Set it pending and activate the softirq: */ set_bit(irq, irqs_resend); tasklet_schedule(&resend_tasklet);