Messages in this thread | | | Subject | Re: [PATCH] irqchip/versatile-fpga: Handle chained IRQs properly | From | Sungbo Eo <> | Date | Thu, 19 Mar 2020 03:20:13 +0900 |
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Hi Marc,
On 2020-03-19 02:48, Marc Zyngier wrote: > 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.
Oops, I missed it. Thanks for pointing it out.
> >> 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.
It seems the handler had been broken from the very beginning. Could you give me a hint on how the tag should be like?
Thanks.
> > Thanks, > > M.
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