On Thu, Dec 27, 2018 at 04:48:19PM +0530, Anup Patel wrote: > We have two enteries (one for M-mode and another for S-mode) in the > interrupts-extended DT property of PLIC DT node for each HART. It is > expected that firmware/bootloader will set M-mode HWIRQ line of each > HART to 0xffffffff (i.e. -1) in interrupts-extended DT property > because Linux runs in S-mode only. > > If firmware/bootloader is buggy then it will not correctly update > interrupts-extended DT property which might result in a plic_handler > configured twice. This patch adds a warning in plic_init() if a > plic_handler is already marked present. This warning provides us > a hint about incorrectly updated interrupts-extended DT property. > > Signed-off-by: Anup Patel <[email protected]> > Reviewed-by: Christoph Hellwig <[email protected]> > --- > drivers/irqchip/irq-sifive-plic.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/irqchip/irq-sifive-plic.c > b/drivers/irqchip/irq-sifive-plic.c > index 01bbbbffbcae..b9a0bcefe426 100644 > --- a/drivers/irqchip/irq-sifive-plic.c > +++ b/drivers/irqchip/irq-sifive-plic.c > @@ -229,6 +229,11 @@ static int __init plic_init(struct device_node *node, > > cpu = riscv_hartid_to_cpuid(hartid); > handler = per_cpu_ptr(&plic_handlers, cpu); > + if (handler->present) { > + pr_warn("handler already present for context %d.\n", i); > + continue; > + } > +
Just use WARN_ON_ONCE?
