... and not if the maximum is non-zero. This fixes the typo introduced
in 47356eb6 and preserves the backlight value from boot.

[ickle: My thanks also to Indan Zupancic for diagnosing the original
        regression and suggesting the appropriate fix.]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org # after 47356eb6

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As the mappable portion of the aperture is always a small subset at the
start of the GTT, it is allocated preferentially by drm_mm. This is
useful in case we ever need to map an object later. However, if you have
a large object that can consume the entire mappable region of the
GTT this prevents the batchbuffer from fitting and so causing an error.
Instead allocate all those that require a mapping up front in order to
improve the likelihood of finding sufficient space to bind them.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Rather than evicting an object at random, which is unlikely to alleviate
the memory pressure sufficient to allow us to continue, zap the entire
aperture. That should give the system long enough to recover and reap
some pages from the evicted objects, forestalling the allocation error
for the new object.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... and not leave the objects in a inconsistent state.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

Before releasing the lock in order to copy the relocation list from user
pages, we need to drop all the object references as another thread may
usurp and execute another batchbuffer before we reacquire the lock.
However, the code was buggy and failed to clear the list...
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

Useful for determining the layout.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In order to retire active buffers whilst no client is active, we need to
insert our own flush requests onto the ring.

This is useful for servers that queue up some rendering and then go to
sleep as it allows us to the complete processing of those requests,
potentially making that memory available again much earlier.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Dave Airlie spotted that his ILK laptop with DMAR enabled was generating
the occasional DMAR warning.

"The ordering in the previous code was to rewrite the GTT table before
unmapping the pages and that makes sense to me."

This is his stable patch ported to d-i-n.
Reported-by: NDave Airlie <airlied@redhat.com>
Original-patch-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The docs recommend that if 8 display lines fit inside the FIFO buffer,
then the number of watermark entries should be increased to hide the
latency of filling the rest of the FIFO buffer.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... in order to avoid a BUG() and potential unbounded waits.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

FDI and the transcoders can fail for various reasons, so detect those
conditions and report on them.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Cleanup several aspects of the rc6 code:
  - misnamed intel_disable_clock_gating function (was only about rc6)
  - remove commented call to intel_disable_clock_gating
  - rc6 enabling code belongs in its own function (allows us to move the
    actual clock gating enable call back into restore_state)
  - allocate power & render contexts up front, only free on unload
    (avoids ugly lazy init at rc6 enable time)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[ickle: checkpatch cleanup]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Enabling RC6 implies setting a graphics context.  Make sure we do that
only after the ring has been enabled, otherwise our ring commands will
hang.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Re-enable rc6 support on Ironlake for power savings.  Adds a debugfs
file to check current RC state, adds a missing workaround for Ironlake
MI_SET_CONTEXT instructions, and renames MCHBAR_RENDER_STANDBY to
RSTDBYCTL to match the docs.

Keep RC6 and the power context disabled on pre-ILK.  It only seems to
hang and doesn't save any power.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As the IMR for the USER interrupts are not modified elsewhere, we can
separate the spinlock used for these from that of hpd and pipestats.
Those two IMR are manipulated under an IRQ and so need heavier locking.
Reported-and-tested-by: NAlexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... and move it under the spinlock to gain the appropriate memory
barriers.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32752Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Otherwise we may consume 20% of the CPU just handling IRQs whilst
rendering. Ouch.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We need to ensure that writes through the GTT land before any
modification to the MMIO registers and so must impose a mandatory write
barrier when flushing the GTT domain. This was revealed by relaxing the
write ordering by experimentally mapping the registers and the GATT as
write-combining.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As has_gem is unconditionally set to true, the conditional immediately
following that assignment is superfluous.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

These functions need to be reworked for Ironlake and above, but until
then at least avoid reading non-existent registers.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[ickle: combine with a gratuitous tidy]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

When bringing up new hardware, or otherwise experimenting, GPU hangs are
a way of life. However, the automatic GPU reset can do more harm than
good under these circumstances, as we may wish to capture a full trace for
debugging.

Based on a patch by Zhenyu Wang.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

On Ironlake, the LP0 latency is hardcoded and in ns unit, while on
Sandybridge, it comes from a register and with unit 0.1 us. So, fix
the wrong latency value while computing wm0 on Ironlake and Sandybridge.
Signed-off-by: NYuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This patch actually makes the watermark code even uglier (if that's
possible), but has the advantage of sharing code between SNB and ILK at
least.  Longer term we should refactor the watermark stuff into its own
file and clean it up now that we know how it's supposed to work.

Supporting WM2 on my Vaio reduced power consumption by around 0.5W, so
this patch is definitely worthwhile (though it also needs lots of test
coverage).
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[ickle: pass the watermark structs arounds]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

On i830 if the tail pointer is set to within 2 cachelines of the end of
the buffer, the chip may hang. So instead if the tail were to land in
that location, we pad the end of the buffer with NOPs, and start again
at the beginning.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

There should be no difference, but we can eliminate redundant code.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In some configuration, the PCU may allow us to overclock the GPU.
Check for this case and adjust the max frequency as appropriate.  Also
initialize the min/max frequencies to default values as indicated by
hardware.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... and just any combination of bits & ~PFIT_ENABLE. This way we do not
attempt disable to the panel fitter controller uselessly upon
intel_lvds_disable().
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

By tracking the current status of the backlight we can prevent recording
the value of the current backlight when we have disabled it. And so
prevent restoring it to 'off' after an unbalanced sequence of
intel_lvds_disable/enable.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=22672Tested-by: NAlex Riesen <raa.lkml@gmail.com>
Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

Alex Fiestas reported an issue with his HDMI connector being misdetected
as DVI unless he had something connected upon boot. By moving the
decision as to whether to use HDMI or DVI encoding for the HDMI capable
output until we probe the monitor means that we should avoid sending a
HDMI signal to a DVI monitor and also correctly detect hardware like
Alex's.

However, to really determine what connector is soldered onto the wire we
need to inspect the VBT sdvo child devices - but can we trust it?
Reported-by: NAlex Fiestas <alex@eyeos.org>
Tested-by: NAlex Fiestas <alex@eyeos.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32828Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

Some voltage swing/pre-emphasis level use the same value on eDP
Sandybridge, like 400mv_0db and 600mv_0db are with the same value
of (0x0 << 22). So, fix them, and point out the value if it isn't
a supported voltage swing/pre-emphasis level.
Signed-off-by: NYuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

Since Linux 2.6.36 the digital output on my system (855GME + DVI-I) is
not working any longer. The analog output is always activated
regardless of the type of monitor attached.

The culprit seems to be intel_crt_detect_ddc(), which returns true as
soon as an ACK from the EDID device is received. Obviously this
approach does not work with DVI-I where the analog and digital outputs
share a common DDC bus.

In a similar manner to the shared DDC wire, ala the "Mac Mini Hack", we
need an additional check to make sure that there really is an analog
device attached to the DDC.
Signed-off-by: NDavid Müller <d.mueller@elsoft.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

When trying to do channel equalization, we need to make sure we still
have clock recovery on all lanes while training.  We also need to try
clock recovery again if we lose the clock or if channel eq fails 5
times.  We'll try clock recovery up to 5 more times before giving up
entirely.

Gets suspend/resume working on my Vaio again and brings us back into
compliance with the DP training sequence spec.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We were using a stale pointer in the check which caused us to use CPU
attached DP params when we should have been using PCH attached params.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31988Tested-by: NJan-Hendrik Zab <jan@jhz.name>
Tested-by: NChristoph Lukas <christoph.lukas@gmx.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

Lots of HDMI TVs overscan the incoming image by default.
The underscan option was added as a way to compensate for
that by underscanning the image so that the edges would
not be cut off on an overscanning TV.  However, the TV
provides no way of knowing whether it is overscanning or
not.  If the user has disabled overscan on their TV or has a
TV that does not overscan, you will get black bars around the
edges of your screen.  Prior to the patch we got complaints
and bug reports from users with overscanning TVs, now with
the patch, we get lots of complaints and bug reports from
users with non-overscanning TVs.  There's no good default,
but on average there have been more users complaining about
it being on by default than off, so change it to off.  This
will probably result in a new deluge of overscanning TV user
complaints.  There's no winning.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This avoids some issues in the current hdmi audio code for monitors
without audio.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>