In order to improve our diagnostic capabilities following a GPU hang
and subsequent reset, we need to record the batch buffer that triggered
the error. We assume that the current batch buffer, plus a few details
about what else is on the active list, will be sufficient -- at the very
least an improvement over nothing.
The extra information is stored in /debug/dri/.../i915_error_state
following an error, and may be decoded using
intel_gpu_tools/tools/intel_error_decode.
v2: Avoid excessive work under spinlocks.
v3: Include ringbuffer for later analysis.
v4: Use kunmap correctly and record more buffer state.
v5: Search ringbuffer for current batch buffer
v6: Use a work fn for the impossible IRQ error case.
v7: Avoid non-atomic paths whilst in IRQ context.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
The ironlake render p-state support includes some rather odd variable
names. Clean them up in order to improve the readability of the code.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Ironlake (and 965GM, which this patch doesn't support) supports a
hardware performance and power management feature that allows it to
adjust to changes in GPU load over time with software help. The goal
if this is to maximize performance/power for a given workload.
This patch enables that feature, which is also a requirement for
supporting Intelligent Power Sharing, a feature which allows for
dynamic budgeting of power between the CPU and GPU in Arrandale
platforms.
Tested-by: ykzhao <yakui.zhao@intel.com>
[anholt: Resolved against the irq handler loop removal]
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Enabling memory self refresh (SR) on 9xx needs to set additional
register bits. On 945, we need bit 31 of FW_BLC_SELF to enable the
write to self refresh bit and bit 16 to enable the write of self
refresh watermark. On 915, bit 12 of INSTPM is used to enable SR.
SR will take effect when CPU enters C3+ state and its entry/exit
should be automatically controlled by H/W, driver only needs to set
SR enable bits in wm update. But this isn't safe in my test on 945
because GPU is hung. So this patch explicitly enables SR when GPU
is idle, and disables SR when it is busy. In my test on a netbook of
945GSE chipset, it saves about 0.8W idle power.
Signed-off-by: Li Peng <peng.li@intel.com>
[anholt: rebased against 33c5fd121e
by adding disable of INSTPM SR bit on 915GM for two pipe setup]
Signed-off-by: Eric Anholt <eric@anholt.net>
On 945, we need to avoid entering self-refresh if the compressor is
busy, or we may cause display FIFO underruns leading to ugly flicker.
Fixes fdo bug #24314, kernel bug #15043.
Tested-by: Alexander Lam <lambchop468@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Julien Cristau <jcristau@debian.org> (fd.o #25371)
Cc: stable@kernel.org
Signed-off-by: Eric Anholt <eric@anholt.net>
Enable/disable the dithering for LVDS based on VBT setting. On the 965/g4x
platform the dithering flag is defined in LVDS register. And on the ironlake
the dithering flag is defined in pipeconf register.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This patch changes around our hotplug enable code a bit to only enable
it for ports we actually detect and initialize. This prevents problems
with stuck or spurious interrupts on outputs that aren't actually wired
up, and is generally more correct.
Fixes FDO bug #23183.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
IGD* isn't a useful name. Replace with the codenames, as sourced from
pci.ids.
Signed-off-by: Adam Jackson <ajax@redhat.com>
[anholt: Fixed up for merge with pineview/ironlake changes]
Signed-off-by: Eric Anholt <eric@anholt.net>
This is a sync of a fix I made in the old UMS code. If the BIOS uses
the GMBUS and doesn't clear that setup, then our bit-banging I2C can
fail, leading to monitors not being detected.
Signed-off-by: Eric Anholt <eric@anholt.net>
Otherwise, I'd get stuck in a loop where (afaict) output scan would
trigger a TV interrupt, which would trigger a scan, etc. TV load
detection not being the fastest thing in the world, X would process
requests very slowly.
https://bugs.freedesktop.org/show_bug.cgi?id=24404
Signed-off-by: Adam Jackson <ajax@redhat.com>
Acked-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Jakob Bornecrantz <jakob@vmware.com>
Acked-by: Thomas Hellström <thomas@shipmail.org>
Review-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse "Orange Smoothie" Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
HW guys have an evaluation about the impact about EOS, and say the impact
is quite small, so they have removed EOS detection support. This patch
removes EOS feature.
revert commit 0430296558
directly reverting it gives a hunk error, so please use this one.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
[anholt: fixed up commit message for update that the feature's really gone]
This implements intel overlay support for kms via a device-specific
ioctl. Thomas Hellstrom brought up the idea of a general ioctl (on
dri-devel). We've reached the conclusion that such an infrastructure
only makes sense when multiple kms overlay implementations exists,
which atm don't (and it doesn't look like this is gonna change).
Open issues:
- Runs in sync with the gpu, i.e. unnecessary waiting. I've decided
to wait on this because the hw tends to hang when changing something
in this area. I left some dummy functions as infrastructure.
- polyphase filtering uses a static table.
- uses uninterruptible sleeps. Unfortunately the alternatives may
unnecessarily wedged the hw if/when we timeout too early (and
userspace only overloaded the batch buffers with stuff worth a few
secs of gpu time).
Changes since v1:
- fix off-by-one misconception on my side. This fixes fullscreen
playback.
Changes since v2:
- add underrun detection as spec'ed for i965.
- flush caches properly, fixing visual corruptions.
Changes since v4:
- fix up cache flushing of overlay memory regs.
- killed require_pipe_a logic - it hangs the chip.
Tested-By: diego.abelenda@gmail.com (on a 865G)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[anholt: Resolved against the MADVISE ioctl going in before this one]
Signed-off-by: Eric Anholt <eric@anholt.net>
Render standy allows the GPU to power down the render unit when idle.
In order for this to work, it needs a page of graphics memory to save
state. This patch allocates that page and enables the feature on
supported chipsets.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Turns out G4x needs to have sensible watermarks set, especially for
self-refresh enabled modes. Add support for it.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Dirk Hohndel <hohndel@infradead.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Must set filter selection as hardcoded coefficients for medium 3x3
filtering, which matches vbios setting for Ironlake.
This fixes display corrupt issue on HP arrandale with new vbios.
Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
For new stepping of PCH, the display reference clock
is fully under driver's control. This one trys to setup
all needed reference clock for different outputs. Older
stepping of PCH chipset should be ignoring this.
This fixes output failure issue on newer PCH which requires
driver to take control of reference clock enabling.
Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Turns out some machines, like the ThinkPad X40 don't come back if you
don't save/restore this register.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
FDI M/N calculation hasn't taken the current pipe color depth into account,
but always set as 24bpp. This one checks current pipe color depth setting,
and change FDI M/N calculation a little to use bits_per_pixel first, then
convert to bytes_per_pixel later.
This fixes display corrupt issue on Arrandle LVDS with 1600x900 panel
in 18bpp dual-channel mode.
Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
According to the spec the LVDS_BORDER_ENABLE bit decides whether the border
data should be included in the active display and data sent to the panel.
Border should be used when in VGA centered (un-scaled) mode or when scaling
a 4:3 source image to a wide screen panel (typical 16:9).
So when the LVDS scaling is used, decide whether the LVDS_BORDER should be
enabled or not according to the current scaling mode.
At the same time fix the typo error in LVDS center scaling mode.
https://bugs.freedesktop.org/show_bug.cgi?id=23789
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
tested-by: Zhao Jian <jian.zhao@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: (57 commits)
drm/i915: Handle ERESTARTSYS during page fault
drm/i915: Warn before mmaping a purgeable buffer.
drm/i915: Track purged state.
drm/i915: Remove eviction debug spam
drm/i915: Immediately discard any backing storage for uneeded objects
drm/i915: Do not mis-classify clean objects as purgeable
drm/i915: Whitespace correction for madv
drm/i915: BUG_ON page refleak during unbind
drm/i915: Search harder for a reusable object
drm/i915: Clean up evict from list.
drm/i915: Add tracepoints
drm/i915: framebuffer compression for GM45+
drm/i915: split display functions by chip type
drm/i915: Skip the sanity checks if the current relocation is valid
drm/i915: Check that the relocation points to within the target
drm/i915: correct FBC update when pipe base update occurs
drm/i915: blacklist Acer AspireOne lid status
ACPI: make ACPI button funcs no-ops if not built in
drm/i915: prevent FIFO calculation overflows on 32 bits with high dotclocks
drm/i915: intel_display.c handle latency variable efficiently
...
Fix up trivial conflicts in drivers/gpu/drm/i915/{i915_dma.c|i915_drv.h}
Add support for framebuffer compression on GM45 and above. Removes
some unnecessary I915_HAS_FBC checks as well (this is now part of the
FBC display function).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
VGA arb requires DRM support for non-kms drivers, to turn on/off
irqs when disabling the mem/io regions.
VGA arb requires KMS support for GPUs where we can turn off VGA
decoding. Currently we know how to do this for intel and radeon
kms drivers, which allows them to be removed from the arbiter.
This patch comes from Fedora rawhide kernel.
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch puts in place the machinery to attempt to reset the GPU. This
will be used when attempting to recover from a GPU hang.
Signed-off-by: Owain G. Ainsworth <oga@openbsd.org>
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Arrandale has new window based method for panel fitting.
This one enables full screen aspect scaling on LVDS. It fixes
standard mode display failure on LVDS for Arrandale.
Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch adds framebuffer compression (good for about ~0.5W power
savings in the best case) support for pre-GM45 chips. GM45+ have a new,
more flexible FBC scheme that will be added in a separate patch.
FBC can't always be enabled: the compressed buffer must be physically
contiguous and reside in stolen space. So if you have a large display
and a small amount of stolen memory, you may not be able to take
advantage of FBC. In some cases, a BIOS setting controls how much
stolen space is available. Increasing this to 8 or 16M can help.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
It seems that on IGDNG the same swizzling setup always applys.
And front buffer tiling needs to set address swizzle in display
arb control too.
Fix plane tricle feed setting in v1 which should be disable bit,
and always setup address swizzle to let hardware care for buffer
tiling in all cases.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
There are several sources of unnecessary power consumption on Intel
graphics systems. The first is the LVDS clock. TFTs don't suffer from
persistence issues like CRTs, and so we can reduce the LVDS refresh rate
when the screen is idle. It will be automatically upclocked when
userspace triggers graphical activity. Beyond that, we can enable memory
self refresh. This allows the memory to go into a lower power state when
the graphics are idle. Finally, we can drop some clocks on the gpu
itself. All of these things can be reenabled between frames when GPU
activity is triggered, and so there should be no user visible graphical
changes.
Signed-off-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
In the event that any one of the DAC analog outputs (R,G,B) were driven
at full-scale (white video) or some analog level close to full-scale
voltage, and if the video cable were then disconnected, the analog video
voltage level would exceed the maximum electrical overstress limit of the
native (thin-oxide) transistors thus causing a long-term reliability concern.
The electrical overstress condition occurs in this particular case.
This patch address the IGD EOS (electrical overstress condition) issue.
When the EOS interrupt occurs, OS should disable DAC and then disable EOS,
then the normal hotplug operation follows.
TODO: it appears the normal unplug interrupt is missed as reported by Li Peng,
need more checks here.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This adds embedded DisplayPort support on next mobile chip which
aims to replace origin LVDS port. VBT's driver feature block has
been used to determine the type of current internal panel for eDP
or LVDS.
Currently no panel fitting support for eDP and backlight control
would be added in future.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
During pipe DPMS off, instead of busy waiting pipe off, insert
delays during wait and don't loop after enough tries which matches
spec requirement. Also try to match DPMS on path by disable FDI TX
PLL in DPMS off. Disable PF by writing PF_WIN_SZ which really trigger
the update.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
I discovered several bugs in the FIFO code that was recently applied.
Some of them fell into the "how did this ever work" category, since in
some cases we were using the wrong FIFO size values, and the
calculations ended up being way off.
This patch fixes all the bugs I found, and works well on my GM45, 915GM
and 855GM test machines; but as usual with these sorts of patches
broader testing is definitely requested (in particular this patch
affects 830, 845 and 865 for which I don't have test hardware).
Overall, the patch clarifies the watermark calculation function by
adding some comments and debug info, and making the variable names a
bit clearer. The "get FIFO size" portion of the code has also been
corrected, so we should be able to properly detect the FIFO allocations
for each pipe, for use in the watermark calculation.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
This patch from jbarnes and myself adds FIFO watermark control to the
driver. This is needed for both power saving features on new platforms
with the so-called "big FIFO" and for controlling FIFO allocation
between pipes in multi-head configurations.
It's also necessary infrastructure to support things like framebuffer
compression and configuration supportability checks (i.e. checking a
configuration against available bandwidth).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This patch enables error detection by enabling several types of error
interrupts. When an error interrupt is received, the interrupt
handler captures the error state; hopefully resulting in an accurate
set of error data (error type, active head pointer, etc.). The new
record is then available from sysfs. The current code will also dump
the error state to the system log.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Previously the driver would always scale the chosen video mode to fill the
panel. This adds 1:1 and maintain-aspect-ratio scaling modes.
v2: the drm_calloc/drm_free is replaced by kzalloc/kfree based
on Eric's suggestion.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This adds the register definitions for the display port enable register
along with those for the GMCH and Link M/N ratios required to drive display
port outputs.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
We detect TV connect status by setting DAC voltage level override
values as 0.7 voltage for DAC_A/B/C. The corresponding 2-bits shold be 0x2,
In order correctly to set last bit as 0, at first we must clean it.
It fixed freedesktop.org bug #21204
Signed-off-by: Ma Ling <ling.ma@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
The pitch field is an exponent on pre-965, so we were rejecting buffers
on 8xx that we shouldn't have. 915 got lucky in that the largest legal
value happened to match (8KB / 512 = 0x10), but 8xx has a smaller tile width.
Additionally, we programmed that bad value into the register on 8xx, so the
only pitch that would work correctly was 4096 (512-1023 pixels), while others
would probably give bad rendering or hangs.
Signed-off-by: Eric Anholt <eric@anholt.net>
fd.o bug #20473.
For some reason we never added 8xx desktop cursor support to the
kernel. This patch fixes that.
[krh: Also set the size on pre-i915 hw.]
Tested-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
In IGD, DPCUNIT_CLOCK_GATE_DISABLE bit should be set, otherwise i2c
access will be wrong.
v2: Disable CLOCK_GATE_DISABLE bit after bit bashing as suggested by Eric.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This patch corrects a pretty big oversight in the KMS code for 965+
chips. The current code is missing tiled surface register programming,
so userland can allocate a tiled surface and use it for mode setting,
resulting in corruption. This patch fixes that, allowing for tiled
front buffers on 965+.
Cc: stable@kernel.org
Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Add VGA port hotplug detection to the i915 driver. When KMS is enabled,
plugging in or removing a VGA cable from the VGA connector will
generate a uevent, which indicates to userspace that it should re-probe
outputs on this device (to determine modes, etc.).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[anholt: dropped extra PORT_HOTPLUG_STAT clear with ack from jbarnes]
Signed-off-by: Eric Anholt <eric@anholt.net>
This fixes all the tiling problems with the 2d ddx. glxgears still doesn't work.
Changes:
- fix a copy&paste error in i8xx fence reg setup. It resulted in an at most a
512KB offset of the fence reg window, so was only visible sometimes.
- add tests for stride and object size constrains (also for i915 and 1965 class
hw). Userspace seems to have an of-by-one bug there, which changes the fence
size by at most 512KB due to an overflow.
- because i8xx hw is quite old (and therefore not as well-tested) I left 2 debug
WARN_ONs in the i8xx fence reg setup code to hopefully catch any further
overflows in the bit-fields. Lastly there's one small change to make the
alignment checks more consistent.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=20289
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Eric Anholt <eric@anholt.net>
Fix TV control save register for untouched bits, and color
knobs different definition for 945 and 965 chips.
Signed-off-by: Zhenyu Wang <zhenyu.z.wang@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This covers:
Use long crt hotplug activation time on GM45.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
The last 8 fence registers sit at a different offset, so when we went to set
fence number 8 in the lower offset, we instead set PGETBL_CTL, and the GPU
got all sorts of angry at us.
fd.o bug #20567. Easily reproducible by running glxgears and killing it about
6 times.
Signed-off-by: Eric Anholt <eric@anholt.net>
As discussed in the long thread about vblank related timeouts, it turns out
GM45 has different frame count registers than previous chips. This patch
adds support for them, which prevents us from waiting on really stale
sequence values in drm_wait_vblank (which rather than returning immediately
ends up timing out or getting interrupted).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
Adds code to set up fence registers at execbuf time on pre-965 chips as
necessary. Also fixes up a few bugs in the pre-965 tile register support
(get_order != ffs). The number of fences available to the kernel defaults
to the hw limit minus 3 (for legacy X front/back/depth), but a new parameter
allows userspace to override that as needed.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
This is ported directly from the userland 2D driver code. The HDMI audio bits
aren't hooked up yet.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
Use the new core GEM object mapping code to allow GTT mapping of GEM
objects on i915. The fault handler will make sure a fence register is
allocated too, if the object in question is tiled.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This fixes readpixels and buffer corruption when swapped out and in by
disabling tiling on them.
Now that we know that the bit 17 mode isn't just a mistake of older chipsets,
we'll need to work on a clever fix so that we can get the performance of
tiling on these chipsets, but that will require intrusive changes targeted
at the next kernel release, not this one.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This register is set by the 2D driver to prevent lockups, and so it needs to
be preserved across suspend/resume too. This makes my X200s work.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
GEM allows the creation of persistent buffer objects accessible by the
graphics device through new ioctls for managing execution of commands on the
device. The userland API is almost entirely driver-specific to ensure that
any driver building on this model can easily map the interface to individual
driver requirements.
GEM is used by the 2d driver for managing its internal state allocations and
will be used for pixmap storage to reduce memory consumption and enable
zero-copy GLX_EXT_texture_from_pixmap, and in the 3d driver is used to enable
GL_EXT_framebuffer_object and GL_ARB_pixel_buffer_object.
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>
