This reverts commit f3637a5f2e.
It turns out that this breaks several drivers, one example being OMAP
boards which use the on-board OMAP UARTs and the omap-serial driver that
will not boot to userspace after the commit.
Paul Walmsley reports that enabling CONFIG_DEBUG_SHIRQ reveals 'IRQ
handler type mismatch' errors:
IRQ handler type mismatch for IRQ 74
current handler: serial idle
...
and the reason is that setting IRQF_ONESHOT will now result in those
interrupt handlers having different IRQF flags, and thus being
unsharable. So the commit log in the reverted commit:
"Since it is required for those users and
there is no difference for others it makes sense to add this flag
unconditionally."
is simply not true: there may not be any difference from a "actions at
irq time", but there is a *big* difference wrt this flag testing irq
management (see __setup_irq() in kernel/irq/manage.c).
One solution may be to stop verifying IRQF_ONESHOT in __setup_irq(), but
right now the safe course of action is to revert the change. Let's
revisit this in a later merge window.
Reported-by: Paul Walmsley <paul@pwsan.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Requested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
69dd3d8e29