Messages in this thread | | | Date | Wed, 18 Mar 2020 17:48:06 +0000 | From | Marc Zyngier <> | Subject | Re: [PATCH] irqchip/versatile-fpga: Handle chained IRQs properly |
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Hi Sungbo,
On 2020-03-18 17:09, Sungbo Eo wrote: > Enclose the chained handler with chained_irq_{enter,exit}(), so that > the > muxed interrupts get properly acked. > > This patch also fixes a reboot bug on OX820 SoC, where the jiffies > timer > interrupt is never acked. The kernel waits a clock tick forever in > calibrate_delay_converge(), which leads to a boot hang.
Nice catch.
> > Signed-off-by: Sungbo Eo <mans0n@gorani.run> > Cc: Neil Armstrong <narmstrong@baylibre.com> > --- > drivers/irqchip/irq-versatile-fpga.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/irqchip/irq-versatile-fpga.c > b/drivers/irqchip/irq-versatile-fpga.c > index 928858dada75..08faab2fec3e 100644 > --- a/drivers/irqchip/irq-versatile-fpga.c > +++ b/drivers/irqchip/irq-versatile-fpga.c > @@ -6,6 +6,7 @@ > #include <linux/irq.h> > #include <linux/io.h> > #include <linux/irqchip.h> > +#include <linux/irqchip/chained_irq.h> > #include <linux/irqchip/versatile-fpga.h> > #include <linux/irqdomain.h> > #include <linux/module.h> > @@ -68,12 +69,15 @@ static void fpga_irq_unmask(struct irq_data *d) > > static void fpga_irq_handle(struct irq_desc *desc) > { > + struct irq_chip *chip = irq_desc_get_chip(desc); > struct fpga_irq_data *f = irq_desc_get_handler_data(desc); > u32 status = readl(f->base + IRQ_STATUS); > > + chained_irq_enter(chip, desc); > +
It's probably not a big deal, but I'm not fond of starting talking to the muxing irqchip before having done the chained_irq_enter() call.
Moving that read here would probably be safer.
> if (status == 0) { > do_bad_IRQ(desc); > - return; > + goto out; > } > > do { > @@ -82,6 +86,9 @@ static void fpga_irq_handle(struct irq_desc *desc) > status &= ~(1 << irq); > generic_handle_irq(irq_find_mapping(f->domain, irq)); > } while (status); > + > +out: > + chained_irq_exit(chip, desc); > } > > /*
Otherwise looks good. If you send it again with the above fixed and a Fixes: tag, I'll queue it.
Thanks,
M. -- Jazz is not dead. It just smells funny...
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