When we takeover from the BIOS and install our interrupt handler, the
BIOS may have left us a few surprises in the form of spontaneous
interrupts. (This is especially likely on hardware like 965gm where
display fifo underruns are continuous and the GMCH cannot filter that
interrupt souce.) As we enable our IRQ early so that we can use it
during hardware probing, our interrupt handler must be prepared to
handle a few sources prior to being fully configured. As such, we need
to add a simple is-ready check prior to dereferencing our KMS state for
reporting underruns.
Reported-by: Rob Clark <rclark@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1193972
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
[Jani: dropped the extra !]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
The comment for intel_cpu_fifo_underrun_irq_handler() is not consistent
with the code and the rest of the comment for this routine. This patch
fixes this typo in comment.
Signed-off-by: Kumar Amit Mehta <gmate.amit@gmail.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This simplifies the code in the vlv irq handler. Also this now
means that we correctly filter underruns on gen2-4.
And as the real upshot I need to document one less function for
the fifo underrun code.
v2: Shorten one long line.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Way too much copypasta all over. And this also clarifies a bit what's
going on since it separates the "do we have an underrun irq" from the
"should we report the underrun" check.
v2: Fix excessively long lines.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Prep work for some nice documentation. Requires that we export the
display irq enable/disable functions on ilk/ibx. But we already export
them for vlv/i915. So not more inconsistency.
v2: Rebase on top of skl stage 1.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
