Hi Juergen,
On 08/02/2021 10:22, Jürgen Groß wrote:
On 08.02.21 10:54, Julien Grall wrote:
... I don't really see how the difference matter here. The idea is to
re-use what's already existing rather than trying to re-invent the
wheel with an extra lock (or whatever we can come up).
The difference is that the race is occurring _before_ any IRQ is
involved. So I don't see how modification of IRQ handling would help.
Roughly our current IRQ handling flow (handle_eoi_irq()) looks like:
if ( irq in progress )
{
set IRQS_PENDING
return;
}
do
{
clear IRQS_PENDING
handle_irq()
} while (IRQS_PENDING is set)
IRQ handling flow like handle_fasteoi_irq() looks like:
if ( irq in progress )
return;
handle_irq()
The latter flow would catch "spurious" interrupt and ignore them. So it
would handle nicely the race when changing the event affinity.
Cheers,
--
Julien Grall
