Messages in this thread | | | From | Michael Schmitz <> | Subject | Re: [PATCH 09/17] [m68k] IRQ: add handle_polled_irq() for timer based soft interrupts | Date | Thu, 7 Nov 2013 20:59:40 +1300 |
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Thomas,
>>>> This is a temporary hack to allow timer based polling of the >>>> Atari ROM port network and USB cards only. Suggestions on how to >>>> properly handle this in the normal interrupt framework are most >>>> welcome. > > So you're polling devices which have no hardware interrupt from the > timer interrupt. Of course if there is no interrupt pending on one of > these devices, this will trigger the spurious detector. By setting the > POLL_INPROGRESS flag, you're preventing that.
That's the general idea, yes. I am aware I abuse the flag somewhat. This was the least invasive fix I came up with (i.e. no risk to cause regressions elsewhere). Adding a new IRQ flag would have been my preference, but that seemed a bit bold at the time.
> Reading the demultiplex handler it seems you have no way to figure out > which of the sub interrupts actually triggered the mfptimer_handler, > right?
Correct.
> I'm not too happy about the POLL flag "abuse". I'd rather have such
Precisely why I asked for this to be reviewed, thanks,
> interrupts explicitely marked as polled by some other interrupt. That > also excludes such interrupts from the spurious mechanism completely. > > Does the following patch solve the problem? You need to call > > irq_set_status_flags(irq, IRQ_IS_POLLED); > > when setting up the interrupt controller for those polled interrupt > lines.
This should do the trick, from what I can see. I have tried to test it, but recent changes to the m68k vmlinux.lds have thrown a monkey wrench in the works, it seems (kernels just won't boot at all). I'll sort that out with Geert and report back.
Much obliged,
Michael
> > Thanks, > > tglx > ----------------- > diff --git a/include/linux/irq.h b/include/linux/irq.h > index 56bb0dc..7dc1003 100644 > --- a/include/linux/irq.h > +++ b/include/linux/irq.h > @@ -70,6 +70,9 @@ typedef void (*irq_preflow_handler_t)(struct > irq_data *data); > * IRQ_MOVE_PCNTXT - Interrupt can be migrated from process context > * IRQ_NESTED_TRHEAD - Interrupt nests into another thread > * IRQ_PER_CPU_DEVID - Dev_id is a per-cpu variable > + * IRQ_IS_POLLED - Always polled by another interrupt. Exclude > + * it from the spurious interrupt detection > + * mechanism and from core side polling. > */ > enum { > IRQ_TYPE_NONE = 0x00000000, > @@ -94,12 +97,14 @@ enum { > IRQ_NESTED_THREAD = (1 << 15), > IRQ_NOTHREAD = (1 << 16), > IRQ_PER_CPU_DEVID = (1 << 17), > + IRQ_IS_POLLED = (1 << 18), > }; > > #define IRQF_MODIFY_MASK \ > (IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \ > IRQ_NOAUTOEN | IRQ_MOVE_PCNTXT | IRQ_LEVEL | IRQ_NO_BALANCING | \ > - IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID) > + IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID > | \ > + IRQ_IS_POLLED) > > #define IRQ_NO_BALANCING_MASK (IRQ_PER_CPU | IRQ_NO_BALANCING) > > diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h > index 1162f10..3320b84 100644 > --- a/kernel/irq/settings.h > +++ b/kernel/irq/settings.h > @@ -14,6 +14,7 @@ enum { > _IRQ_NO_BALANCING = IRQ_NO_BALANCING, > _IRQ_NESTED_THREAD = IRQ_NESTED_THREAD, > _IRQ_PER_CPU_DEVID = IRQ_PER_CPU_DEVID, > + _IRQ_IS_POLLED = IRQ_IS_POLLED, > _IRQF_MODIFY_MASK = IRQF_MODIFY_MASK, > }; > > @@ -26,6 +27,7 @@ enum { > #define IRQ_NOAUTOEN GOT_YOU_MORON > #define IRQ_NESTED_THREAD GOT_YOU_MORON > #define IRQ_PER_CPU_DEVID GOT_YOU_MORON > +#define IRQ_IS_POLLED GOT_YOU_MORON > #undef IRQF_MODIFY_MASK > #define IRQF_MODIFY_MASK GOT_YOU_MORON > > @@ -147,3 +149,8 @@ static inline bool > irq_settings_is_nested_thread(struct irq_desc *desc) > { > return desc->status_use_accessors & _IRQ_NESTED_THREAD; > } > + > +static inline bool irq_settings_is_polled(struct irq_desc *desc) > +{ > + return desc->status_use_accessors & _IRQ_IS_POLLED; > +} > diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c > index 7b5f012..a1d8cc6 100644 > --- a/kernel/irq/spurious.c > +++ b/kernel/irq/spurious.c > @@ -67,8 +67,13 @@ static int try_one_irq(int irq, struct irq_desc > *desc, bool force) > > raw_spin_lock(&desc->lock); > > - /* PER_CPU and nested thread interrupts are never polled */ > - if (irq_settings_is_per_cpu(desc) || > irq_settings_is_nested_thread(desc)) > + /* > + * PER_CPU, nested thread interrupts and interrupts explicitely > + * marked polled are excluded from polling. > + */ > + if (irq_settings_is_per_cpu(desc) || > + irq_settings_is_nested_thread(desc) || > + irq_settings_is_polled(desc)) > goto out; > > /* > @@ -268,7 +273,8 @@ try_misrouted_irq(unsigned int irq, struct > irq_desc *desc, > void note_interrupt(unsigned int irq, struct irq_desc *desc, > irqreturn_t action_ret) > { > - if (desc->istate & IRQS_POLL_INPROGRESS) > + if (desc->istate & IRQS_POLL_INPROGRESS || > + irq_settings_is_polled(desc)) > return; > > /* we get here again via the threaded handler */ > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-m68k" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
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