Sometimes both acpi video and i915 driver are compiled as modules.
And there exists the strict dependency between the two drivers.
The acpi video bus will be unloaded in course of unloading the i915 driver.
If we unload the acpi video driver, then the kernel oops will be triggered.
Add the reference count to avoid unloading the ACPI video bus twice.
The reference count should be checked before unregistering the acpi video bus.
If the reference count is already zero, it won't unregister it again.
And after the acpi video bus is already unregistered, the reference count
will be set to zero.
http://bugzilla.kernel.org/show_bug.cgi?id=13396
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The changes to opregion initialisation order meant that the ASLE setup
code might not be run at the correct time. Ensure that the interrupts are
set up.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
The i915 DRM triggers registration of the ACPI video driver on load. It
should unregister it at unload in order to avoid generating backtraces on
being reloaded.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
The ACPI video driver defers registration to the i915 driver if the
system supports opregion-mediated backlight control. This registration
was only being performed in the KMS case. Ensure it's done even if we
don't have modesetting enabled.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Intel graphics hardware that implements the ACPI IGD OpRegion spec
requires that the list of display devices be populated before any ACPI
video methods are called. Detect when this is the case and defer
registration until the opregion code calls it. Fixes crashes on HP
laptops.
http://bugzilla.kernel.org/show_bug.cgi?id=11259
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Len Brown <len.brown@intel.com>
The pipestat fields affect reporting of all vblank-related interrupts, so we
have to reset them during the irq_handler, and while enabling vblank
interrupts. Otherwise, if a pipe status field had been set to non-zero
before enabling reporting, we would never see an interrupt again.
This patch adds i915_enable_pipestat and i915_disable_pipestat to abstract
out the steps needed to change the reported interrupts.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This adds the support necessary for allowing ACPI backlight control to
work on some newer Intel-based graphics systems. Tested on Thinkpad T61
and HP 2510p hardware.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>
Zhao Yakui