On Sat, 14 Nov 2020 11:05:08 +0300 Serge Belyshev <belyshev@xxxxxxxxxxxxxxxxx> wrote:
> Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> writes:
>
> > On Fri, 13 Nov 2020 14:58:32 +0100 Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:
> >
> >> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> >>
> >> in_interrupt() is true for a variety of things including bottom half
> >> disabled regions. Deducing hard interrupt context from it is dubious at
> >> best.
> >>
> >> Use in_irq() which is true if called in hard interrupt context. Otherwise
> >> calling irq_exit() would do more harm than good.
> >>
> >
> > Gee, how to test it. Does anyone run current kernels on alpha?
>
> Hold my beer:
>
> --- a/arch/alpha/kernel/process.c
> +++ b/arch/alpha/kernel/process.c
> @@ -134,8 +134,10 @@ common_shutdown_1(void *generic_ptr)
> #ifdef CONFIG_DUMMY_CONSOLE
> /* If we've gotten here after SysRq-b, leave interrupt
> context before taking over the console. */
> - if (in_irq())
> + if (in_irq()) {
> + printk ("in_irq(): true\n");
> irq_exit();
> + }
> /* This has the effect of resetting the VGA video origin. */
> console_lock();
> do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
>
>
> and then sysrq-b over serial console:
>
> [ 56.531250] sysrq: Resetting
> [ 56.531250] in_irq(): true
> [ 56.531250] Console: switching to colour dummy device 80x25
>
> halted CPU 0
>
> halt code = 5
> HALT instruction executed
> PC = fffffc0000310040
> Resetting I/O buses...
> >>>
>
> Tested-by: Serge Belyshev <belyshev@xxxxxxxxxxxxxxxxx>
Thanks ;)
Here, have that beer back - I kept some for you.
