Correct a merge mishap in

commit e4443e45
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Wed Apr 9 13:28:41 2014 +0300

    drm/i915/chv: Add a bunch of pre production workarounds

Remove the the chv specific workarounds from bdw code, specifically
gen8_enable_rps().
Signed-off-by: NTom O'Rourke <Tom.O'Rourke@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[Jani: extract hunk #1 for 3.16 from Tom's patch, clarify commit message]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

---

All, I intend to push this to drm-intel-fixes, any objections?

Jani.

If the timer putting the last forcewake refcount was pending and we
canceled it, we'll leak the corresponding forcewake and RPM references.

v2:
- do the ptr casting at the caller instead of adding a separate helper
  for this (Chris)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

If a semaphore is waiting on another ring, which in turn happens to be
waiting on the first ring, but that second semaphore has been signalled,
we will be able to kick the second ring and so can treat the first ring
as a valid WAIT and not as HUNG.

v2: Be paranoid and cap the potential recursion depth whilst visiting
the semaphore signallers. (Mika)

References: https://bugs.freedesktop.org/show_bug.cgi?id=54226
References: https://bugs.freedesktop.org/show_bug.cgi?id=75502Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Otherwise we print out spurious processes on unused rings in the error
state.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

For reasons I can't claim to fully understand gen4 seems to require
backlight duty cycle setting after the backlight has been enabled, or
else black screen follows. I don't have documentation for the correct
sequence on gen4 either. Confirmed on Dell Latitude D630 and MacBook4,1.

This fixes a regression introduced by
commit b35684b8
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Thu Nov 14 12:13:41 2013 +0200

    drm/i915: do full backlight setup at enable time

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=75791
Reported-and-tested-by: mcy@lm7.fr
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79423Reported-and-tested-by: NMarc Milgram <mmilgram@redhat.com>
Cc: Stable <stable@vger.kernel.org> # 3.14+
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

On certain platforms pixel_multiplier is read out in
.get_pipe_config(), but it also gets used to calculate the
pixel clock in intel_sdvo_get_config(). If the pipe is disable
but some SDVO outputs are active, we may end up dividing by zero
in intel_sdvo_get_config().

To avoid the problem simply check for zero pixel_multiplier and skip
the division. Another attempt at fixing this involved populating
pixel_multiplier to 1 even for disabled pipes, but that triggered a
WARN because SDVO_CMD_GET_CLOCK_RATE_MULT command failed and thus
encoder_pixel_multiplier was left at zero and didn't match
pipe_config->pixel_multiplier.

The "divide by pixel_multiplier" operation got introduced here:
 commit 18442d08
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Fri Sep 13 16:00:08 2013 +0300

    drm/i915: Fix port_clock and adjusted_mode.clock readout all over

and it has caused a regression on certain machines since they would
hit the div-by-zero during resume.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76520
Cc: <stable@vger.kernel.org> # 3.13+
Tested-by: NTim Richardson <tim@tim-richardson.net>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

It causes black screen on bootup and is approximately 100x slower than
running with FBC disabled, so the GPU runs at a high frequency for much
longer - completely contrary to the power saving claims. It also still
has mutex deadlocks in multi-head scenarios, which can lead to a
system/X lockup. These bugs were known before FBC was enabled by default
on Haswell and still have not been fixed.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79716Reported-and-tested-by: NJon Kristensen <info@jonkri.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
[Jani: update subject to reflect the actual change]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

I cannot see a need to provide a DRM_ version of ARRAY_SIZE(), only used
in a few places. I suspect its usage has been spread by copy & paste
rather than anything else.

Let's just remove it for plain ARRAY_SIZE().
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Touching the VGA resources on an IVB EFI machine causes hard hangs when
we then kick out the efifb. Ouch.

Apparently this also prevents unclaimed register errors on hsw and
hard machine hangs on my i855gm when trying to unbind fbcon.

Also, we want this to make I915_FBDEV=n safe.

v2: Rebase and pimp commit message.

v3: We also need to unregister the vga console, otherwise the unbind
of the fb console before module unload might resurrect it again.

v4: Ignore errors when the vga console is already unregistered - this
can happen when e.g. reloading i915.ko.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-fbdev@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The global gtt is setup up in 2 parts, so we need to be careful
with the cleanup. For consistency shovel it all into the ->cleanup
callback, like with ppgtt.

Noticed because it blew up in the out_gtt: cleanup code while
fiddling with the vgacon code.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

BDW uses IVB cursor offsets.

Whithout this patch it is not possible to use multiple outputs with cursor
on BDW.
The cursor gets completely crazy because update position uses the wrong
cursor register for the second pipe.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79621Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Daniel requested in the bug that I use a 3GB fallback size. Since this
is not in the spec as a valid size, I decided against it. We could
potentially add a patch to bump it to 3GB on top of this one.

This probably should be CC: stable - but I'll let the powers that be
decide that one.

Regression from a revert of the revert:
commit 7907f45b
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Wed Feb 19 22:05:46 2014 -0800

    Revert "drm/i915/bdw: Limit GTT to 2GB"

v2: Change ifdef to 32b, instead of ifndef
update comment

v3. Update comment to not wrap (Daniel).
Update commit message

v4: s/CONFIG_32/CONFIG_X86_32 (Jani).

v5: s/CONFIG_x86_32BIT/CONFIG_x86_32, as meant in v4
s/32B/32b (chris)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76619
Cc: stable@vger.kernel.org
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Tested-by: N"Yang, Guang A" <guang.a.yang@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Apparently it does more harm than good. Thomas Richter reports that
it helps his machine (Thinkpad X31) and there's another report from a
Fujitsu S6010. Also, we've nuked it on i845G already to make Chris'
machine happy.

Cc: Thomas Richter <richter@rus.uni-stuttgart.de>
References: http://mid.mail-archive.com/538C54E0.8090507@rus.uni-stuttgart.deSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Atm, we refcount both power domains and power wells and
intel_display_power_enabled_sw() returns the power domain refcount. What
the callers are really interested in though is the sw state of the
underlying power wells. Due to this we will report incorrectly that a
given power domain is off if its power wells were enabled via another
power domain, for example POWER_DOMAIN_INIT which enables all power
wells.

As a fix return instead the state based on the refcount of all power
wells included in the passed in power domain.

References: https://bugs.freedesktop.org/show_bug.cgi?id=79505
References: https://bugs.freedesktop.org/show_bug.cgi?id=79038Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It is possible for userspace to create a big object large enough for a
256x256, and then switch over to using it as a 64x64 cursor. This
requires the cursor update routines to check for a change in width on
every update, rather than just when the cursor is originally enabled.

This also fixes an issue with 845g/865g which cannot change the base
address of the cursor whilst it is active.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[Antti:rebased, adjusted macro names and moved some lines, no functional
changes]
Reviewed-by: NAntti Koskipaa <antti.koskipaa@linux.intel.com>
Tested-by: NAntti Koskipaa <antti.koskipaa@linux.intel.com>
Cc: stable@vger.kernel.org
Testcase: igt/kms_cursor_crc/cursor-size-change
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If both KMS is disabled (by i915.modeset=0 or nomodeset parameters) and
UMS is disabled (by CONFIG_DRM_I915_UMS=n, the default), the user might
not be aware his setup is not supported. Inform the users (and, by
extension, the poor i915 developers having to read their dmesgs in bug
reports) why their graphics experience might be lacking.

A similar message was added on the UMS path in
commit e147accb
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Thu Oct 10 15:25:37 2013 +0300

    drm/i915: tell the user KMS is required for gen6+

but it won't be reached if CONFIG_DRM_I915_UMS=n since
commit b30324ad
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Nov 13 22:11:25 2013 +0100

    drm/i915: Deprecated UMS support

v2: Use DRM_DEBUG_DRIVER.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Some platforms may not have it, and enumerating it is both confusing and
time consuming due to the hotplug and DDC probing.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Gen2 doesn't have the ring idle/stop bits in the SCPD/MI_MODE register,
so don't go spewing warnings about the state of those bits.
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>

If the user tries to mmap through the GTT an object that is marked as
snooped, we report an error rather than allow the GPU to hang the
machine. The choice of EINVAL, however, was unfortunate as we turn that
into a WARN rather than a quiet SIGBUS.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move the MI_ARB_STATE MI_ARB_C3_LP_WRITE_ENABLE setup to
gen3_init_clock_gating() from i915_gem_load() when KMS is enabled. Leave
it in i915_gem_load() for the UMS case, but add an explcit check, just
to make it easier to spot it when we eventually rip out UMS support.
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>

85x also has a similar AGPBUSY# bit as gen3. Enable it to make
sure vblank interrupts don't get dealyed during C3 state.

There's also another bit which controls whether AGPBUSY# is asserted
based on pending cacheable cycles and interrupts, or just based on
pending commands in the ring and interrupts. Select the cacheable
cycles mode since that seems to be the new way of doing things in
85x, and it does give slightly better C3 residency numbers with
glxgears running.
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>

My Gen3 Bspec lists the AGPBUSY# bit in INSTPM as an enable bit rather
than a disable bit. Our code has the opposite idea. Make the code match
the spec.

Might fix some gen3 C3 related interrupt delivery problems. Untested
due to lack of hardware.

v2: call it AGPBUSY_INT_EN to make it clearer it has to do with interrupts
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>

I don't see why we wouldn't want interrupts to wake up the CPU from C3
always, so just set the AGPBUSY# bit in gen3_init_clock_gating().
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>

When doing this, all PLLs should be disabled.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to do this anytime we power gate the DPIO common well.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There may be a dependency here.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This needs to be done before we power back on the CMN_BC well so the PHY
can calibrate properly.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We do this at runtime and later on now.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is a bit like the CMN reset de-assert we do in DPIO_CTL, except
that it resets the whole common lane section of the PHY.  This is
required on machines where the BIOS doesn't do this for us on boot or
resume to properly re-calibrate and get the PHY ready to transmit data.

Without this patch, such machines won't resume correctly much of the time,
with the symptom being a 'port ready' timeout and/or a link training
failure.

Note that simply asserting reset at suspend and de-asserting at resume
is not sufficient, nor is simply de-asserting at boot.  Both of these
cases have been tested and have still been found to have failures on
some configurations.

v2: extract simpler set_power_well function for use in reset_dpio (Imre)
    move to reset_dpio (Daniel & Ville)
v3: don't reset if DPIO reset is already de-asserted (Imre)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we disable first the port (by disabling DPI) and only then the
display pipe the pipe-off flag will never be set, possibly leading to a
hanged pipe state at the next modeset-enable.

Note that according to the VLV2 display cluster HAS, we should disable
the port before the pipe. This doesn't seem to match reality based on
the above and it's also asymmetric with the enabling sequence, where we
first enable the port and then the pipe.

v2:
- send the panel shutdown command before stopping the pipe, since this
  is the recommended sequence (Shobhit)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NShobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It seems by default the VBT has MIPI configuration block as well. The
Generic driver will assume always MIPI if MIPI configuration block is found.
This is causing probelm when actually there is eDP. Fix this by looking
into general definition block which will have device configurations. From here
we can figure out what is the LFP type and initialize MIPI only if MIPI
is found.

v2: Addressed review comments by Damien
    - Moved PORT definitions to intel_bios.h and renamed as DVO_PORT_MIPIA
    - renamed is_mipi to has_mipi and moved definition as suggested
    - Check has_mipi inside parse_mipi and intel_dsi_init insted of outside

v3: Make has_mipi as a bitfield as suggested
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: fold in conditions to pack everything neatly below 80 chars.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For disabling L3 clock gating we need to set bit 25 of MMIO
register 940c. Earlier this was being done by just writing 1
into bit 25 and resetting all other bits.
This patch modifies the routine to read-modify-write of the
register, so that the values of other bits are not destroyed.

v2: Modifying the comments and the patch commit message (Chris)
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Signed-off-by: NSourab Gupta <sourab.gupta@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Apply checkpatch fixup.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This driver makes use of the generic panel information from the VBT.
Panel information is classified into two - panel configuration and panel
power sequence which is unique to each panel. The generic driver uses the
panel configuration and sequence parsed from VBT block #52 and #53

v2: Address review comments by Jani
    - Move all of the things in driver c file from header
    - Make all functions static
    - Make use of video/mipi_display.c instead of redefining
    - Null checks during sequence execution

v3: Address review comments by Damien
    - Rename the panel driver file as intel_dsi_panel_vbt.c
    - Fix style changes as suggested
    - Correct comments for lp->hs and hs->lp count calculations
    - General updating comments to have more clarity
    - using max() instead of ternary operator
    - Fix names (ui_num, ui_den) while using UI in calculations
    - compute max of lp_to_hs switch and hs_to_lp switch while computing
      hs_lp_switch_count
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fallout from an intermediate patch revision that I deemed worth saving.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we do a full re-init of all interrupts after a gpu hang.
Which is pretty bad since we don't restore the interrupts we've
enabled at runtime correctly. Even with that addressed it's rather
horribly race.

But on g4x and later we only reset the gt and not the entire gpu.
Which means we only need to reset the GT interrupt bits. Which has the
nice benefit that vblank waits, pipe CRC interrupts and everything
else display related just keeps on working.

The downside is that gt interrupt handling (i.e. ring->get/put_irq) is
still racy. But as long as the gpu hang reliably wakes all waters and
we have a short time where the refcount drops to 0 we'll recover. So
not that bad really.

v2: Ville noticed that GTIMR and PMIMR don't get cleared, only the
subordinate per-ring registers. So let's rip out all the interrupt dancing.
The FIXME comment is still required though since the ring irq handling
happens at the per-ring interrupt mask registers, too.

Testcase: igt/kms_flip/vblank-vs-hang
Testcase: igt/kms_pipe_crc_basic/hang-*
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No point in having this indirection.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Ville figured out that it needs a full display reset since apparently
a lot more goes down than just the GT. Until that's address it's
better to just diable gpu reset.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So apparently this is tricky.

We need to consider:
- We start out with all the hw enabling bits disabled, both the
  individual fifo underrun interrupts and the shared display error
  interrupts masked. Otherwise if the bios config is broken we'll blow
  up with a NULL deref in our interrupt handler since the crtc
  structures aren't set up yet at driver load time.
- On gmch we need to mask fifo underruns on the sw side, so always
  need to set that in sanitize_crtc for those platforms.
- On other platforms we try to set the sw tracking so that it reflects
  the real state. But since a few platforms have shared bits we must
  _not_ disable fifo underrun reporting. Otherwise we'll never enable
  the shared error interrupt.

This is the state before out patch, but unfortunately this is not good
enough. But after a suspend resume operation this is broken:
1. We don't enable the hw interrupts since the same code runs on
resume as on driver load.
2. The fifo underrun state adjustments we do in sanitize_crtc doesn't
fire on resume since (except for hilarious firmware) all pipes are off
at that point. But they also don't hurt since the subsequent crtc
enabling due to force_restore will enable fifo underruns.

Which means when we enable fifo underrun reporting we notice that the
per-crtc state is already correct and short-circuit everthing out. And
the interrupt doesn't get enabled.

A similar problem would happen if the bios doesn't light up anything
when the driver loads. Which is exactly what happens when we reload
the driver since our unload functions disables all outputs.

Now we can't just rip out the short-circuit logic and unconditionally
update the fifo underrun reporting interrupt masking: We have some
checks for shared error interrupts to catch issues that happened when
the shared error interrupt was disabled.

The right fix is to push down this logic so that we can always update
the hardware state, but only check for missed fifo underruns on a real
enabled->disabled transition and ignore them when we're already
disabled.

On platforms with shared error interrupt the pipe CRC interrupts are
grouped together with the fifo underrun reporting this fixes pipe CRC
support after suspend and driver reloads.

Testcase: igt/kms_pipe_crc_basic/suspend-*
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On platforms with shared interrupt enable bits (which are shared even
with the pipe CRC logic) there's some tricky corner cases. Add
information to make debugging those easier.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

All drm_fb_helper_restore_fbdev_mode() call sites, save one, do the same
locking.  Simplify this into drm_fb_helper_restore_fbdev_mode_unlocked().
Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>