drm/i915: use in_interrupt() not in_irq() to check context

drm/i915: use in_interrupt() not in_irq() to check context

commit 6c51d46f135b00c00373fcd029786ccef2b02b5b upstream.

The kernel in_irq() function tests for hard-IRQ context only, so if a
system is run with the kernel 'threadirqs' option selected, the test in
intel_check_page_flip() generates lots of warnings, because then it gets
called in soft-IRQ context.

We can instead use in_interrupt() which allows for either type of
interrupt, while still detecting and complaining about misuse of the
page flip code if it is ever called from non-interrupt context.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89321
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>