Messages in this thread | | | From | Valentin Schneider <> | Subject | Re: [RFC PATCH] irqchip/gic: Implement irq_chip->irq_retrigger() | Date | Fri, 10 Jul 2020 18:08:01 +0100 |
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On 10/07/20 17:29, Marc Zyngier wrote: > On Fri, 10 Jul 2020 15:56:42 +0100, > Valentin Schneider <valentin.schneider@arm.com> wrote:
[...]
>> Implement irq_chip.irq_retrigger() for both GICs. > > Although I am very grateful for the whole documentation, I'd rather > have a slightly more condensed changelog that documents the > implementation of the retrigger callback! ;-) >
Hah, indeed! I was relatively unsure about that whole thing, hence why I sent it as RFC with a wall of text attached. I'll probably strip out the GIC doc snippets for the "actual" changelog, and talk about the *contents* of the patch some more.
>> >> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> >> --- >> drivers/irqchip/irq-gic-v3.c | 7 +++++++ >> drivers/irqchip/irq-gic.c | 6 ++++++ >> 2 files changed, 13 insertions(+) >> >> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c >> index cc46bc2d634b..c025e8b51464 100644 >> --- a/drivers/irqchip/irq-gic-v3.c >> +++ b/drivers/irqchip/irq-gic-v3.c >> @@ -1207,6 +1207,11 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, >> #define gic_smp_init() do { } while(0) >> #endif >> >> +static int gic_retrigger(struct irq_data *data) >> +{ >> + return gic_irq_set_irqchip_state(data, IRQCHIP_STATE_PENDING, true); > > If I'm not mistaken, check_irq_resend() requires a non-zero return > value if the retrigger has succeeded. So something like > > return !gic_irq_set_irqchip_state(data, IRQCHIP_STATE_PENDING, true); > > would be more appropriate. >
Aye, you're right. And while we're at it, we probably still don't want to fallback to irq_sw_resend() if the retrigger fails, so we should add some irqd_set_handle_enforce_irqctx() somewhere in the GICs or plainly deselect CONFIG_HARDIRQS_SW_RESEND.
I'm not very familiar with LPIs just yet, but seeing as they too use handle_fasteoi_irq() and can't get retriggered, I'd rather play it safe.
This brings me to another point: while this boots just fine, I didn't get to test out IRQs marked with IRQS_PENDING. IIUC enable_irq_wake() should give me a decent trail - I see serial_core making use of it. I'll go give suspend a try.
> Otherwise, looks good. >
Thanks for having a look!
> Thanks, > > M.
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