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Since irq_work is used for deferred MSR handling, > any atomic console printing when entering cpuidle states can lead > to the affected hardware hanging. Tegra20 and Tegra30 are examples > of such platforms. Avoiding raising the irq_work IRQ has shown to > circumvent the problem. > > Change the console_msr_work to be IRQ_WORK_LAZY, thus not raising > an IRQ upon irq_work queuing. The irq_work is then handled on the > next interrupt (worst case, kernel tick). > > Link: https://lore.kernel.org/lkml/f3757a75-0ba1-4558-bf57-f19ab7e59a4c@nvidia.com > Fixes: d3539347022a ("serial: 8250: Switch to nbcon console, take 2") > Signed-off-by: John Ogness > --- > drivers/tty/serial/8250/8250_port.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c > index 38fa45e74a37a..1acb73e45f8a0 100644 > --- a/drivers/tty/serial/8250/8250_port.c > +++ b/drivers/tty/serial/8250/8250_port.c > @@ -3597,7 +3597,7 @@ int serial8250_console_setup(struct uart_port *port, char *options, bool probe) > > up->console_line_ended = true; > up->console_msr_work_allow = true; > - init_irq_work(&up->console_msr_work, console_msr_handler); > + up->console_msr_work = IRQ_WORK_INIT_LAZY(console_msr_handler); > > if (options) > uart_parse_options(options, &baud, &parity, &bits, &flow); FWIW ... Tested-by: Jon Hunter Thanks! Jon -- nvpublic