This was introduced in:

commit 7c4a395f
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Wed Oct 9 19:17:56 2013 +0300

    drm/i915: Don't re-compute pipe watermarks except for the affected pipe

and I missed fixing it in:

commit fec8cba3
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Wed Nov 27 11:10:26 2013 -0800

    drm/i915: use crtc_htotal in watermark calculations to match fastboot v2

It's needed for ILK+ platforms to fastboot without crashing on a divide
by 0 after a DPMS on action.

Note: Ville mentioned in his review that this confusion seems to go
down to the original introduction of this code in

commit 801bcfff
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Fri May 31 10:08:35 2013 -0300

    drm/i915: properly set HSW WM_PIPE registers

So it seems to have been missed both in the fastboot patch and in the
3d mode suppport (where only crtc_htotal reflects the real pipe
width).
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Add note based on Ville's review.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Avoid duplicating the same piece of code several times by separating
the watemark vfunc setup from the init_clock_gating vfunc setup on PCH
platforms.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We forgot to intialize the watermark vfuncs for BDW, and hence the
watermarks were never updated.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Looks like I forgot to update the ILK/SNB/IVB watermark patches to deal
with BDW. Add the relevant BDW checks to make sure we take the HSW
codepaths on BDW as well.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We use this hook starting from ILK onwards, so change the prefix
accordingly. Also rename functions/struct names used from
haswell_update_wm that are relevant to ILK already.

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No functional change.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We now have a very clear method of disabling LP1+ wartermarks,
and we can actually detect if we actually did disable them, or
if they were already disabled. Use that to clean up the
WaCxSRDisabledForSpriteScaling:ivb handling.

I was hoping to apply the workaround in a way that wouldn't
require a blocking wait, but sadly IVB really does appear to
require LP1+ watermarks to be off for an entire frame before
enabling sprite scaling. Simply disabling LP1+ watermarks
during the previous frame is not enough, no matter how early
in the frame we do it :(
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The new HSW watermark code can now handle ILK/SNB/IVB as well, so
switch them over. Kill the old code.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ILK doesn't like if we just write the LP1+ watermarks registers with 0.
We need to just disable the watermarks by clearing the enable bit. Use
that method also when disabling LP1+ watermarks in init_clock_gating.

It looks like disabling the sprite LP1 watermarks can cause underruns
even if we just toggle the WM1S_LP_EN bit. So treat that bit like the
actual watermark numbers and avoid setting it to 0 immediately.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Linetime watermarks don't exist on ILK/SNB/IVB, so don't compute them
except on HSW.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ILK has a bunch of issues with FBC. First of all, BSpec tells us that
FBC WM should never be enabled. Secondly when FBC is enabled
with FBC WM disabled, LP2+ watermarks must be disabled.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Multi-pipe LP1+ watermarks are a HSW+ feature, so let's not do it on
earlier generations.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On ILK disabling LP1+ watermarks must be done carefully to avoid
underruns. If we just write 0 to the register in the middle of the scan
cycle we often get an underrun. So instead we have to leave the actual
watermark levels in the register intact, and just toggle the enable bit.

Presumably the hardware takes a while to get out of low power mode, and
so the watermark level need to stay valid until that time.

We also have to be careful with the WM1S_LP_EN bit. It seems the
hardware more or less treats it like the actual watermarks numbers, and
so we must not toggle it too soon. Just leave it alone when disabling
the LP1+ watermarks.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ILK/SNB don't have LP2+ watermarks for sprites. Also the LP1 sprite
watermark register has its own enable bit. Take these differences
into account when programming the LP1+ registers.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On ILK/SNB only LP0/1 watermarks can be enabled when sprites are
enabled, and on ILK/SNB/IVB sprite scaling is limited to LP0 only.

So we can avoid computing the extra levels we're never going to use.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a new function  ilk_wm_lp_latency() which will tell us what to write
into the WM_LPx register latency field. HSW is different from erlier
gens in this regard.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On IVB the display data buffer partitioning control lives in the
DISP_ARB_CTL2 register. Add the relevant defines/code for it.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

WaVSRefCountFullforceMissDisable and
WaDSRefCountFullforceMissDisable

VS is a carry-over from HSW, and DS is likely not used by anyone yet.

Cc: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Line of 106 chars is too long. Really.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I stumbled on to some unimplemented errata. To be honest, I am not
really sure of the impact, just that the docs say to do.

No w/a name for this one.

v2: v1 was a stale thing which should have never seen the light of day.
(Haihao)

Cc: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Don't touch DPFC_RECOMP_CTL on FBC2, use RMW to update
the FBC_CONTROL on FBC1 to make it easier for people to
experiment with different numbers. Also fix the interval
mask for FBC1.

v2: Rebased
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Gen2 and gen3 don't have the FBC_CONTROL2 register, so don't
touch it.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On gen2 the compressed frame buffer pitch is specified in 32B units
rather than the 64B units used on gen3+.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fixes regression introduced by:
    commit bf51d5e2
    Author: Paulo Zanoni <paulo.r.zanoni at intel.com>
    Date:   Wed Jul 3 17:12:13 2013 -0300
        drm/i915: switch disable_power_well default value to 1

The bug I'm seeing can be reproduced with:
  - Have vgacon configured/enabled
  - Make sure the power well gets disabled, then enabled. You can
    check this by seeing the messages print by hsw_set_power_well
  - Stop your display manager
  - echo 0 > /sys/class/vtconsole/vtcon1/bind

I can easily reproduce this by blacklising snd_hda_intel and booting
with eDP+HDMI.

If you do this and then look at dmesg, you'll see we're printing
infinite "Unclaimed register" messages. This is happening because
we're stuck on an infinite loop inside console_unlock(), which is
calling many functions from vgacon.c. And the code that's triggering
the error messages is from vgacon_set_cursor_size().

After we re-enable the power well, every time we read/write the VGA
address 0x3d5 we get an "unclaimed register" interrupt (ERR_INT) and
print error messages. If we write anything to the VGA MSR register (it
doesn't really matter which value you write to bit 0), any
reads/writes to 0x3d5 _don't_ trigger the "unclaimed register" errors
anymore (even if MSR bit 0 is zero). So what happens with the current
code is that when we unbind i915 and bind vgacon, we call
console_unlock(). Function console_unlock() is responsible for
printing any messages that were supposed to be print when the console
was locked, so it calls the TTY layer, which calls the console layer,
which calls vgacon to print the messages. At this point, vgacon
eventually calls vgacon_set_cursor_size(), which touches 0x3d5, which
triggers unclaimed register interrupts. The problem is that when we
get these interrupts, we print the error messages, so we add more work
to console_unlock(), which will try to print it again, and then call
vgacon again, trigger a new interrupt, which will put more stuff to
the buffer, and then we'll be stuck at console_unlock() forever.

If you patch intel_uncore.c to not print anything when we detect
unclaimed registers, we won't get into the console_unlock() infinite
loop and the driver unbind will work just fine. We will still be
getting interrupts every time vgacon touches those registers, but we
will survive. This is a valid experiment, but IMHO it's not the real
fix: if we don't print any error messages we will still keep getting
the interrupts, and if we disable ERR_INT we won't get the interrupt
anymore, but we will also stop getting all the other error interrupts.

I talked about this problem with the HW engineer and his
recommendation is "So don't do any VGA I/O or memory access while the
power well is disabled, and make to re-program MSR after enabling the
power well and before using VGA I/O or memory accesses.".

Notice that this is just a partial fix to fd.o #67813. This fixes the
case where the power well is already enabled when we unbind, not when
it's disabled when we unbind.

V2: - Rebase (first version was sent in September).
V3: - Complete rewrite of the same fix: smaller implementation,
      improved commit message.

Testcase: igt/drv_module_reload
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I want to add more code to the post_enable function.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch adds the initial infrastructure to allow a Runtime PM
implementation that sets the device to its D3 state. The patch just
adds the necessary callbacks and the initial infrastructure.

We still don't have any platform that actually uses this
infrastructure, we still don't call get/put in all the places we need
to, and we don't have any function to save/restore the state of the
registers. This is not a problem since no platform uses the code added
by this patch. We have a few people simultaneously working on runtime
PM, so this initial code could help everybody make their plans.

V2: - Move some functions to intel_pm.c
    - Remove useless pm_runtime_allow() call at init
    - Remove useless pm_runtime_mark_last_busy() call at get
    - Use pm_runtime_get_sync() instead of 2 calls
    - Add a WARN to check if we're really awake

V3: - Rebase.

V4: - Don't need to call pci_{save,restore}_state and
      pci_set_power_sate, since they're already called by the PCI
      layer
    - Remove wrong pm_runtime_enable() call at init_runtime_pm
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In the current code, at haswell_modeset_global_resources, first we
decide if we want to enable/disable the power well, then we decide if
we want to enable/disable PC8. On the case where we're enabling PC8
this works fine, but on the case where we disable PC8 due to a non-eDP
monitor being enabled, we first enable the power well and then disable
PC8. Although wrong, this doesn't seem to be causing any problems now,
and we don't even see anything in dmesg. But the patches for runtime
D3 turn this problem into a real bug, so we need to fix it.

This fixes the "modeset-non-lpsp" subtest from the "pm_pc8" test from
intel-gpu-tools.

v2: - Rebase (i915_disable_power_well).
v3: - More reabase.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Initialize the FBC vfuncs on gen2 and gen3 chipsets. Also make
a clean split for gen7+ vs. gen5+ vfunc initialization.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On gen2 and gen3 chipsets FBC is supported only on plane A. Fix (and
simplify) the plane checks in intel_update_fbc() accordingly.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Atm we call intel_display_power_enabled() from
i915_capture_error_state() in IRQ context and then take a mutex. To fix
this add a new intel_display_power_enabled_sw() which returns the domain
state based on software tracking as opposed to reading the actual HW
state.

Since we use domain_use_count for this without locking on the reader
side make sure we increase the counter only after enabling all required
power wells and decrease it before disabling any of these power wells.

Regression introduced in
commit 1b02383464b4a915627ef3b8fd0ad7f07168c54c
Author: Imre Deak <imre.deak@intel.com>
Date:   Tue Sep 24 16:17:09 2013 +0300

    drm/i915: support for multiple power wells

Note that atm we depend on the value returned by
intel_display_power_enabled_sw() in i915_capture_error_state() to avoid
unclaimed register access reports. This was never guaranteed though,
since another thread can disable the power concurrently. If this is a
problem we need another explicit way to disable the reporting during
error captures.

v2:
- remove barriers as the caller can't depend on the value
  returned from i915_capture_error_state_sw() anyway (Ville)
- dump the state of pipe/transcoder power domain state (Daniel)
Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Setting this bit restores all ring contexts in parallel rather than
serially.  Matches current BWG recommendations.
Tested-by: N"Meng, Mengmeng" <mengmeng.meng@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NDeepak S <deepak.s@inel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We use timeout mode, and we need to lower the timeout to get good RC6
residency when loads are running.  This gets me from 0% residency during
glxgears to 77%, which is a pretty good improvement.  This value also
matches the current BWG recommentations.
Tested-by: N"Meng, Mengmeng" <mengmeng.meng@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NDeepak S <deepak.s@inel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Split vlv force wake routines to help individually control Media/Render
well based on the register access.

We've seen power savings in the lower sub-1W range on workloads that
only need on of the power wells, e.g. glbenchmark, media playback

Note: The same split isn't there for the forcewake queue, only the
forcwake domains are split.
Signed-off-by: NDeepak S <deepak.s@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Rebase on top of the removed forcewake hack in the ring irq
get/put code and add a note to add Deepak's answer to Chris question.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Added power well arguments to all the force wake routines
to help us individually control power well based on the
scenario.
Signed-off-by: NDeepak S <deepak.s@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Resolve conflict with the removed forcewake hack and drop one
spurious hunk Jesse noticed.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a debugfs entry showing the use-count for all power domains of each
power well.

v3: address comments from Paulo:
- simplify power_domain_str() by using a switch table
- move power_well::domain_count to power_domains
- WARN_ON decrementing a 0 refcount
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So far we distinguished platforms without a dynamic power well with
the HAS_POWER_WELL macro and for such platforms we didn't call any power
domain functions. Instead of doing this check we can add an always-on
power well for these platforms and call the power domain functions
unconditionally. For always-on power wells we only increase/decrease
their refcounts, otherwise they are nop.

This makes high level driver code more readable and as a bonus provides
some idea of the current power domains state for all platforms (once
the relevant debugfs entry is added).

v3: rename intel_power_wells to i9xx_always_on_power_well (Paulo)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of using a separate function to check whether a power domain is
is always on, add an always-on power well covering all these power
domains and do the usual get/put on these unconditionally. Since we
don't assign a .set handler for these the get/put won't have any effect
besides the adjusted refcount.

This makes the code more readable and provides debug info also on the
use of always-on power wells (once the relevant debugfs entry is added.)

v3: make is_always_on to be bool instead of a bit field (Paulo)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

HW generations so far had only one always-on power well and optionally
one dynamic power well. Upcoming HW gens may have multiple dynamic power
wells, so add some infrastructure to support them.

The idea is to keep the existing power domain API used by the rest of
the driver and create a mapping between these power domains and the
underlying power wells. This mapping can differ from one HW to another
but high level driver code doesn't need to know about this. Through the
existing get/put API it would just ask for a given power domain and the
power domain framework would make sure the relevant power wells get
enabled in the right order.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This way the code is simpler and can also be used for other platforms
where the audio power domain->power well mapping is different.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>