Two benefits:
- We can use FW_LOADER_USERSPACE_FALLBACK.
- We can use flush_work to synchronize with the oustanding worker,
  which is a notch more obvious what it does than having a special
  completion.

The next patch will properly synchronize against the async loader in
the resume and unload code.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-11-git-send-email-imre.deak@intel.com

The loader function will get a bit more complicated soon, extract the
parsing code to make the control flow clearer. While doing that just
use dev_priv->csr.dmc_payload as the indicator for whether it all
suceeded or not.

v2-v3:
- unchanged
v4:
- rebased on top of latest drm-intel-nightly

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
[imre: remove note about BE cast from commit message, it's not relevant
 any more]
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
[Jani: fix checkpatch warn on multiple blank lines]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447341089-2735-1-git-send-email-imre.deak@intel.com

As all csr firmware related opertion are not using any
any data structures of drm framework level, so better to
use dev_priv instead of dev. it's a new style! :)

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-9-git-send-email-imre.deak@intel.com

We need to make sure we don't put garbage into the hw if dmc firmware
loading failed mid-thru.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-8-git-send-email-imre.deak@intel.com

If we really want to we can be more verbose here, but we really don't
need an entire function for this.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-7-git-send-email-imre.deak@intel.com

Standard is to align continuations of parameter lists and if
conditions to the opening ( in i915 and drm code.

Apply this across the entire file since it was sticking out a bit too
much.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
[imre: removed note about reg definitions from the commit message, it's
 not relevant any more]
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-6-git-send-email-imre.deak@intel.com

This removes two anti-patterns:
- Locking shouldn't be used to synchronize with async work (of any
  form, whether callbacks, workers or other threads). This is what the
  mutex_lock/unlock seems to have been for in intel_csr_load_program.
  Instead ordering should be ensured with the generic
  wait_for_completion()/complete(). Or more specific functions
  provided by the core kernel like e.g.
  flush_work()/cancel_work_sync() in the case of synchronizing with a
  work item.

- Don't invent own completion like the following code did with the
  (already removed) wait_for(csr_load_status_get()) pattern - it's
  really hard to get these right when you want them to be _really_
  correct (and be fast) in all cases. Furthermore it's easier to read
  code using the well-known primitives than new ones using
  non-standard names.

Before enabling/disabling DC6 check if the firmware is loaded
successfully. This is guaranteed during runtime s/r, since otherwise we
don't enable RPM, but not during system s/r.

Note that it's still unclear whether we need to enable/disable DC6
during system s/r, until that's clarified, keep the current behavior and
enable/disable DC6.

Also after this patch there is a race during system s/r where the
firmware may not be loaded yet, that's addressed in an upcoming patch.

v2-v3:
- unchanged
v4:
- rebased on latest drm-intel-nightly

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
[imre: added code and note about checking if the firmware loaded ok,
 before enabling/disabling it]
Reviewed-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447341037-2623-1-git-send-email-imre.deak@intel.com

Avoids non-static functions since all the callers are in intel_rpm.c.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
[imre: removed note about reg definitions from commit message, since
 it's not relevant any more]
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
[Jani: make assert_csr_loaded static]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-4-git-send-email-imre.deak@intel.com

Grabbing a runtime pm reference with intel_runtime_pm_get will only
prevent device D3. But dmc firmware is required even earlier (namely
for the skl power well 2).

Hence we need to grab a rpm reference higher up in the hierarchy. For
simplicity just grab the _INIT display power well. That's a bit too
much, but since the firmware loading task should completely fairly
quickly this won't be a real problem really.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-3-git-send-email-imre.deak@intel.com

Skl is fully dependent on dmc for going to low power state (dc5/dc6).
This requires a trigger from rpm. To ensure the dmc firmware
is available for runtime pm support rpm-reference-count is used
by not releasing the rpm reference if firmware loading is
not completed.

So moved the intel_csr_ucode_init call after runtime pm enable.

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
[imre: moved the call right after power domain init to avoid race with
 the console modesetting]
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Reviewed-by: NA.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-2-git-send-email-imre.deak@intel.com

Have only one if ladder for platforms and only one range check for
size. Makes it easier to handle new platforms. Remove the use of
negative return values in char, which might underflow to be positive for
some negative error codes.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445344713-1407-3-git-send-email-jani.nikula@intel.com

Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445344713-1407-2-git-send-email-jani.nikula@intel.com

Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445344713-1407-1-git-send-email-jani.nikula@intel.com

No need to verify VMA belongs to GGTT since:

1. The function must return a normal VMA belonging to passed in VM.
2. There can only be one normal VMA for any VM.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1447329595-17495-1-git-send-email-tvrtko.ursulin@linux.intel.comSigned-off-by: NJani Nikula <jani.nikula@intel.com>

Minor fixup to d0669d00 ("drm/i915: Clean up LVDS register
handling") which intended to read lvds_reg just once at the
beginning of intel_lvds_init() and use that throughout the rest
of the function but accidentally missed one register readout.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20151107141244.AB7616E242@gabe.freedesktop.orgSigned-off-by: NJani Nikula <jani.nikula@intel.com>

Reading the driver load/unload code leaves one confused as there's
an async_schedule() in the load, but not async_synchronize_full()
in sight. In fact it's hidden inside intel_fbdev.c. So let's move the
async_schedule() into intel_fbdev.c as well so that it's next to the
async_synchronize_full(), which should make the relationship easier
to see.

Plus this way we won't schedule a nop function call when fbdev is
disabled. And we were passing a pointer to a static inline
function to async_schedule(), which seems rather dubious to me.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446815313-9490-4-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

We set up fbdev last during load, so doing the fbdev cleanup should be
first.

We weren't supposed to drop the init power during driver unload, but since
the fbdev teardown happened after intel_power_domains_fini() that could
have happened due in one of two ways. First it could have happened
during the modeset caused by normal fbdev cleanup. But in addition it
could have happened already via the intel_fbdev_initial_config() since
that is executed asynhronously, and the async_synchronize_full() was
done during fbdev cleanup, after intel_power_domains_fini(). All of
that got eliminated by
commit 292b990e ("drm/i915: Update power domains on readout.")
since we now drop the init power synchronously during driver load.

So there is no real bug wrt. the init power anymore, but still it seems
better to do the fbdev cleanup first, before we've potentially cleaned
up something else important.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446815313-9490-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

intel_runtime_pm_disable() takes an extra rpm reference which combined
with the one we leak from intel_display_set_init_power() leaves the
usage count at <original>+1 after the driver has been unloaded.
The original ref is dropped explicitly in intel_runtime_pm_enable().
So the next time we load the driver we can no longer do runtime PM ever.

This used to work, but
commit 292b990e ("drm/i915: Update power domains on readout.")
broke things by not dropping the init power domain during fbdev
teardown. Based on the comment in intel_power_domains_fini(), the
way it used to to work wasn't intentional. As in we weren't supposed
to drop the init power during driver unload. And since we no longer
do, we now leak an extra rpm reference.

So fix things by throwing intel_runtime_pm_disable() to the bin, so
that the only leaked reference comes from the init power domain.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Stone <daniels@collabora.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Fixes: 292b990e ("drm/i915: Update power domains on readout.")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446815313-9490-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Set up the DDI->PLL mapping on SKL also for MST links. Might help make
MST operational on SKL.

v2: Rebased due to KBL
    Improve the patch subject, Jesse provided the new one

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1439826380-18403-1-git-send-email-ville.syrjala@linux.intel.com
References: https://bugs.freedesktop.org/show_bug.cgi?id=91791Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

ironlake_set_pll_cpu_edp() only gets called just before
ironlake_edp_pll_on(), so just pull the code into ironlake_edp_pll_on().

Also toss in a debug print into ironlake_edp_pll_off() to match the one
we have in ironlake_edp_pll_on().
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-15-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use intel_dp->DP in the eDP PLL setup, instead of doing RMWs.

To do this we need to move DP_AUDIO_OUTPUT_ENABLE setup to happen later,
so that we don't enable audio accidentally while configuring the PLL.

Note that actually we already enabled audio before the port due to
the double port register write magic required by VLV/CHV from
7b713f50 ("drm/i915: Fix eDP link training when switching pipes on VLV/CHV")
So that gets changed now to keep audio off as long as the port is off.

Also intel_dp_link_down() must be made to update intel_dp->DP so that we
don't re-enable the port by accident when turning off the PLL. This is
safe now that we don't call intel_dp_link_down() during link retraining.

v2: Add a note about the audio vs. port enable (Daniel)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447164977-32315-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJani Nikula <jani.nikula@intel.com>

Rewrite the eDP PLL state asserts to conform to our usual state assert
style.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-13-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We don't care about ILK-A and the old w/a notes may just confuse
people, so get rid of them.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-12-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The DP link frequency is 162MHz, not 160MHz. Rename the ILK eDP PLL
defines to match.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-11-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We get underruns on the other pipe when enabling the CPU eDP PLL and
port on ILK.

Bspec knows about the PLL issue, and recommends doing a vblank wait just
prior to enabling the PLL. That does seem to help, but unfortunately we
get another underrun when actually enabling the CPU eDP port. Bspec
doesn't mention that at all, and the same vblank wait trick doesn't
appear to be effective there.

Since I have no better clue how to deal with this, just hide the errors.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-10-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Doing the IBX transcoder B workaround causes underruns on
pipe/transcoder A. Just hide them by disabling underrun reporting for
pipe A around the workaround.

It might be possible to avoid the underruns by moving the workaround
to be applied only when enabling pipe A. But I was too lazy to try it
right now, and the current method has been proven to work, so didn't
want to change it too hastily.

Note that this can re-enable underrun reporting on pipe A if was
already disabled due to a previous actual underrun. But that's OK, we
may just get a second underrun report if another real underron occurrs
on pipe A.

v2: Note that pipe A underruns can get re-enabled due to this (Jani)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1446225802-11180-1-git-send-email-ville.syrjala@linux.intel.com

ironlake_enaable_pch_transcoder() checks for CPT to see if it should
enable the timing override chicken bit, but
ironlake_disable_pch_transcoder() checks for !IBX to see if it should
clear the same bit. Change ironlake_disable_pch_transcoder() to check
for CPT as well to keep the two sides consistent.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-8-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Due to the shared error interrupt on IVB/HSW and CPT/PPT we may not
always get an interrupt on a FIFO underrun. But we can always do an
explicit check (like we do on GMCH platforms that have no underrun
interrupt).

v2: Drop stale kerneldoc for i9xx_check_fifo_underruns() (Daniel)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1446225741-11070-1-git-send-email-ville.syrjala@linux.intel.com

Some hardware (IVB/HSW and CPT/PPT) have a shared error interrupt for
all the relevant underrun bits, so in order to keep the error interrupt
enabled, we need to have underrun reporting enabled on all PCH
transocders. Currently we leave the underrun reporting disabled when
the pipe is off, which means we won't get any underrun interrupts
when only a subset of the pipes are active.

Fix the problem by re-enabling the underrun reporting after the pipe has
been disabled. And to avoid the spurious underruns during pipe enable,
disable the underrun reporting before embarking on the pipe enable
sequence. So this way we have the error reporting disabled while
running through the modeset sequence.

v2: Re-enable PCH FIFO underrun reporting unconditionally on pre-HSW
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1446225691-10928-1-git-send-email-ville.syrjala@linux.intel.com

As we did for ILK/SNB/IVB, move the PCH FIFO underrun enable to happen
after the encoder enable on HSW+. And again, for symmetry, move the
the disable to happen before encoder disable.

I've left out the vblank wait before the enable here because I don't
know if it's needed or not. Actually I don't know if this entire
change is needed as I don't have a HSW/BDW with VGA output.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

We get spurious PCH FIFO underruns if we enable the reporting too soon
after enabling the crtc. Move it to be the last step, after the encoder
enable. Additionally we need an extra vblank wait, otherwise we still
get the underruns. Presumably the pipe/fdi isn't yet fully up and running
otherwise.

For symmetry, disable the PCH underrun reporting as the first thing,
just before encoder disable, when shutting down the crtc.

v2: Do the PCH underrun enable unconditionally (Jani, Daniel)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1446225627-10809-1-git-send-email-ville.syrjala@linux.intel.com

Rather than looking at crtc->mode (which is the user mode) dig up the
sync polarity settings from the adjusted_mode when programming
TRANS_DP_CTL on CPT/PPT.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

No point in doing the crtc->pipe->crtc->config->cpu_transcoder dance
when we can just do crtc->config->cpu_transcoder.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>

From our maintainer Daniel Vetter a few days ago:
  "Oh dear this is dead code. kdbg uses the fbcon, which always uses
  untiled, which means fbc will never be enabled. Also we have 0 users
  and 0 test coverage for kdbg on top of i915 (Jesse implemented it
  for fun years back). Imo just remove all this code."

Adding to what Daniel said: for kgdboc's KMS support,
intel_pipe_set_base_atomic() already manually disables FBC, so we
won't do the in_dbg_master() check there. This is essentially a revert
of:

commit c924b934
Author: Jason Wessel <jason.wessel@windriver.com>
Date:   Thu Aug 5 09:22:32 2010 -0500
    i915: when kgdb is active display compression should be off

Besides, it is not clear what is the exact problem caused by FBC, and
why other features such as PSR, DRRS, IPS and RPM are not also
checking for in_dbg_master(). IMHO we should either remove the code as
suggested by Daniel or we add some nice comments explaining why is FBC
so special.

v2: Rebase due to new patch order.

Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1446664257-32012-13-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

Daniel was looking at this code and asked about whether fb->pitches[0]
is correct, then he suggested we should a comment to make sure it is
actually intentional.

For more information on the CFB size calculation, please see the
commit message of:

commit c4ffd409
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Thu Oct 1 19:55:57 2015 -0300
    drm/i915: fix CFB size calculation
Requested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446664257-32012-12-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

If we run igt/kms_frontbuffer_tracking, this message will appear
thousands of times, eating a significant part of our dmesg buffer.
It's part of the expected FBC behavior, so let's just silence it.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446664257-32012-10-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

Make sure we deactivate FBC at intel_fbc_init(), so we can remove the
call from intel_display.c. Currently we only have the "enabled"
software state, but later we'll have both "enabled" and "active", and
we'll add assertions to them, so just calling intel_fbc_disable() from
intel_modeset_init() won't work. It's better to make sure
intel_fbc_init() already puts the hardware in the expected state, so
we can put nice assertions in the other functions.

v2: Keep/improve the comment (Chris).
v3: Improve the commit message a little bit.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446664257-32012-9-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

If FBC is disabled we will still call intel_fbc_invalidate(), and as a
result we may call intel_fbc_deactivate(), which will try to touch
registers.

I'm pretty sure I saw this happen on a runtime suspended device, and
I'm almost sure I was running igt/pm_rpm. It produced the "you touched
registers while the device is suspended" WARNs. But this was some time
ago and I can't remember exactly which conditions were necessary to
reproduce the problem.

v2: Rebase to new series order.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446664257-32012-8-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

Don't try to list in comments the cases where we should enable or
disable FBC: it varies a lot with the hardware generations and the
code should be the documentation. Also notice that there's already a
huge gap between the comments and what's in the code.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>

Link: http://patchwork.freedesktop.org/patch/msgid/1446664257-32012-7-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

This change was part of the commit that makes intel_fbc_update()
receive an intel_crtc as argument instead of dev_priv, but since it
was polluting the diff with too many chunks I decided to move it to
its own commit.

It seems that our developers are favoring having this instead of the
old combination drm_crtc *crtc + intel_crtc *intel_crtc, and on the
mentioned commit we'll get rid of the drm_crtc variable, so let's do
an intermediate commit with the rename, so on the next commit we'll
have just struct intel_crtc *crtc.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446664257-32012-6-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>