i915_gem_request_alloc() uses error pointers.  It never returns NULLs.

Fixes: 0daf0113 ("drm/i915: Mock infrastructure for request emission")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170413195217.GA26108@mwandaReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

If link training at a link rate optimal for a particular
mode fails during modeset's atomic commit phase, then we
let the modeset complete and then retry. We save the link rate
value at which link training failed, update the link status property
to "BAD" and use a lower link rate to prune the modes. It will redo
the modeset on the current mode at lower link rate or if the current
mode gets pruned due to lower link constraints then, it will send a
hotplug uevent for userspace to handle it.

This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4,
4.3.1.6.

This patch is a resend of the original commit id (233ce881
"drm/i915: Implement Link Rate fallback on Link training failure")
which got reverted in this commit id (afc1ebf4 Revert
"drm/i915: Implement Link Rate fallback on Link training failure")
due to CI failures.

After investigating the CI failures it was found that these
were essentially the failures which were always there but hidden because
they used to be DRM_DEBUG_KMS messages for link failures so never got
caught by CI. But now this patch actually throws DRM_ERROR if the link
training fails at RBR and 1 lane. So it caught these link train failures.

There were two failures:
1. On SKL 6700k this was because the machine in CI lab is a SKL desktop
without eDP on Port A. But our VBT initialization code in the driver writes
VBT defaults in a way that it always sets DP flag on Port A and this does
not get cleared after parsing the VBT outputs. This has been fixed in
commit id (bb1d1329 "drm/i915/vbt: split out defaults that are set
when there is no VBT) and (66578857 "drm/i915/vbt: don't propagate
errors from intel_bios_init())

2. On ILK-650 desktop - This was happening because of a bad monitor desktop
combination. I switched the monitor in the CI lab and that helped get rid
of the link failures on ILK system.

v10:
* Rebase on drm-tip and resend after revert
v9:
* Use the trimmed max values of link rate/lane count based on
link train fallback (Daniel Vetter)
v8:
* Set link_status to BAD first and then call mode_valid (Jani Nikula)
v7:
Remove the redundant variable in previous patch itself
v6:
* Obtain link rate index from fallback_link_rate using
the helper intel_dp_link_rate_index (Jani Nikula)
* Include fallback within intel_dp_start_link_train (Jani Nikula)
v5:
* Move set link status to drm core (Daniel Vetter, Jani Nikula)
v4:
* Add fallback support for non DDI platforms too
* Set connector->link status inside set_link_status function
(Jani Nikula)
v3:
* Set link status property to BAd unconditionally (Jani Nikula)
* Dont use two separate variables link_train_failed and link_status
to indicate same thing (Jani Nikula)
v2:
* Squashed a few patches (Jani Nikula)
Acked-by: NTony Cheng <tony.cheng@amd.com>
Acked-by: NHarry Wentland <Harry.wentland@amd.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: NManasi Navare <manasi.d.navare@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/16ca48b1e74c618929245e9a085b9e3483c3a16d.1491485983.git.jani.nikula@intel.com

Apparently some DP sinks are a little nuts and cause HPD to drop
intermittently during modesets. This happens eg. on an ASUS PB287Q.
In oder to recover from this we can't really use the previous
connector status to determine if the link needs retraining, so let's
just ignore that piece of information and do the retrain
unconditionally. We do of course still check whether the link is
supposed to be running or not.

To actually get read out the EDID and update things properly we
also need to nuke the goto out added by commit 7d23e3c3
("drm/i915: Cleaning up intel_dp_hpd_pulse"). I'm actually not sure
why that was there. Perhaps to avoid an EDID read if the connector
status didn't appear to change, but that sort of thing is quite racy
and would have failed anyway if we failed to keep up with the
hotplugs (if we missed the HPD down in between two HPD ups). And
now that we take this codepath unconditionally we definitely need
to drop the goto as otherwise we would never do the EDID read.

v2: Drop the goto that made us skip EDID reads entirely. Doh!
v3: Rebase due to locking changes
    s/apparely/apparently/ in the comment (Chris)

Cc: stable@vger.kernel.org
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Reported-by: NPalmer Dabbelt <palmer@dabbelt.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99766
References: https://lists.freedesktop.org/archives/intel-gfx/2017-February/119779.htmlSigned-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170412193017.21029-1-ville.syrjala@linux.intel.com

The wopcm registers are write-once, so any write after the first one
will just be ignored. The registers survive a GPU reset but not
always a suspend/resume cycle, so to keep things simple keep the
writes in the intel_uc_init_hw function instead of moving it earlier
to make sure we attempt them every time we try to load GuC.

Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491524332-23860-1-git-send-email-daniele.ceraolospurio@intel.com

[31908.547136] BUG: KASAN: use-after-free in intel_lpe_audio_teardown+0x78/0xb0 [i915] at addr ffff8801f7788358
[31908.547297] Read of size 8 by task drv_selftest/3781
[31908.547405] CPU: 0 PID: 3781 Comm: drv_selftest Tainted: G    BU  W       4.10.0+ #451
[31908.547553] Hardware name:                  /        , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015
[31908.547682] Call Trace:
[31908.547772]  dump_stack+0x68/0x9f
[31908.547857]  kasan_object_err+0x1c/0x70
[31908.547947]  kasan_report_error+0x1f1/0x4f0
[31908.548038]  ? kfree+0xaa/0x170
[31908.548121]  kasan_report+0x34/0x40
[31908.548211]  ? klist_children_get+0x20/0x30
[31908.548472]  ? intel_lpe_audio_teardown+0x78/0xb0 [i915]
[31908.548567]  __asan_load8+0x5e/0x70
[31908.548824]  intel_lpe_audio_teardown+0x78/0xb0 [i915]
[31908.549080]  intel_audio_deinit+0x28/0x80 [i915]
[31908.549315]  i915_driver_unload+0xe4/0x360 [i915]
[31908.549551]  ? i915_driver_load+0x1d70/0x1d70 [i915]
[31908.549651]  ? trace_hardirqs_on+0xd/0x10
[31908.549885]  i915_pci_remove+0x23/0x30 [i915]
[31908.549978]  pci_device_remove+0x5c/0x100
[31908.550069]  device_release_driver_internal+0x1db/0x2e0
[31908.550165]  driver_detach+0x68/0xc0
[31908.550256]  bus_remove_driver+0x8b/0x150
[31908.550346]  driver_unregister+0x3e/0x60
[31908.550439]  pci_unregister_driver+0x1d/0x110
[31908.550531]  ? find_module_all+0x7a/0xa0
[31908.550791]  i915_exit+0x1a/0x87 [i915]
[31908.550881]  SyS_delete_module+0x264/0x2c0
[31908.550971]  ? free_module+0x430/0x430
[31908.551064]  ? trace_hardirqs_off_caller+0x16/0x110
[31908.551159]  ? trace_hardirqs_on_caller+0x16/0x280
[31908.551256]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[31908.551350]  entry_SYSCALL_64_fastpath+0x1c/0xb1
[31908.551440] RIP: 0033:0x7f1d67312ec7
[31908.551520] RSP: 002b:00007ffebe34e888 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[31908.551650] RAX: ffffffffffffffda RBX: ffffffff811123f6 RCX: 00007f1d67312ec7
[31908.551743] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000560d0af476b8
[31908.551837] RBP: ffff880233d87f98 R08: 0000000000000000 R09: 00007ffebe34e8b8
[31908.551930] R10: 00007f1d68adf8c0 R11: 0000000000000206 R12: 0000000000000000
[31908.552023] R13: 0000560d0af46440 R14: 0000000000000034 R15: 00007ffebe34d860
[31908.552121]  ? trace_hardirqs_off_caller+0x16/0x110
[31908.552217] Object at ffff8801f7788000, in cache kmalloc-2048 size: 2048
[31908.552306] Allocated:
[31908.552377] PID = 3781
[31908.552456]  save_stack_trace+0x16/0x20
[31908.552539]  kasan_kmalloc+0xee/0x190
[31908.552627]  __kmalloc+0xdb/0x1b0
[31908.552713]  platform_device_alloc+0x27/0x90
[31908.552804]  platform_device_register_full+0x36/0x220
[31908.553066]  intel_lpe_audio_init+0x41e/0x570 [i915]
[31908.553320]  intel_audio_init+0xd/0x40 [i915]
[31908.553552]  i915_driver_load+0x13f5/0x1d70 [i915]
[31908.553788]  i915_pci_probe+0x65/0xe0 [i915]
[31908.553881]  pci_device_probe+0xda/0x140
[31908.553969]  driver_probe_device+0x400/0x660
[31908.554058]  __driver_attach+0x11c/0x120
[31908.554147]  bus_for_each_dev+0xe6/0x150
[31908.554237]  driver_attach+0x26/0x30
[31908.554325]  bus_add_driver+0x26b/0x3b0
[31908.554412]  driver_register+0xce/0x190
[31908.554502]  __pci_register_driver+0xaf/0xc0
[31908.554589]  0xffffffffa0550063
[31908.554675]  do_one_initcall+0x8b/0x1e0
[31908.554764]  do_init_module+0x102/0x325
[31908.554852]  load_module+0x3aad/0x45e0
[31908.554944]  SyS_finit_module+0x169/0x1a0
[31908.555033]  entry_SYSCALL_64_fastpath+0x1c/0xb1
[31908.555119] Freed:
[31908.555188] PID = 3781
[31908.555266]  save_stack_trace+0x16/0x20
[31908.555349]  kasan_slab_free+0xb0/0x180
[31908.555436]  kfree+0xaa/0x170
[31908.555520]  platform_device_release+0x76/0x80
[31908.555610]  device_release+0x45/0xe0
[31908.555698]  kobject_put+0x11f/0x260
[31908.555785]  put_device+0x12/0x20
[31908.555871]  platform_device_unregister+0x1b/0x20
[31908.556135]  intel_lpe_audio_teardown+0x5c/0xb0 [i915]
[31908.556390]  intel_audio_deinit+0x28/0x80 [i915]
[31908.556622]  i915_driver_unload+0xe4/0x360 [i915]
[31908.556858]  i915_pci_remove+0x23/0x30 [i915]
[31908.556948]  pci_device_remove+0x5c/0x100
[31908.557037]  device_release_driver_internal+0x1db/0x2e0
[31908.557129]  driver_detach+0x68/0xc0
[31908.557217]  bus_remove_driver+0x8b/0x150
[31908.557304]  driver_unregister+0x3e/0x60
[31908.557394]  pci_unregister_driver+0x1d/0x110
[31908.557653]  i915_exit+0x1a/0x87 [i915]
[31908.557741]  SyS_delete_module+0x264/0x2c0
[31908.557834]  entry_SYSCALL_64_fastpath+0x1c/0xb1
[31908.557919] Memory state around the buggy address:
[31908.558005]  ffff8801f7788200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[31908.558127]  ffff8801f7788280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[31908.558255] >ffff8801f7788300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[31908.558374]                                                     ^
[31908.558467]  ffff8801f7788380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[31908.558595]  ffff8801f7788400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

v2: Just leak the memory (8 bytes) as freeing it ourselves is not safe,
and we need to coordinate a proper fix in platform_device itself.

Fixes: eef57324 ("drm/i915: setup bridge for HDMI LPE audio driver")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99952Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Jerome Anand <jerome.anand@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20170412080251.30648-1-chris@chris-wilson.co.ukReviewed-by: NTakashi Iwai <tiwai@suse.de>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Currently intel_dp_check_link_status() tries to retrain the link if
Clock recovery or Channel EQ for any of the lanes indicated by
intel_dp->lane_count is not set. However these values cached in intel_dp
structure can be stale if link training has failed for these values
during previous modeset. Or these values can get stale since we have
now re read the DPCD registers or it can be 0 in case of connected boot
case.

This patch validates these values against the max link rate and max lane
count values.

This is absolutely required incase the common_rates or max lane count
are now different due to link fallback.

v2:
* Include the FIXME commnet inside the function (Ville Syrjala)
* Remove the redundant parenthesis (Ville Syrjala)

v3 by Jani:
* rebase on the DP refactoring series
* rename intel_dp_link_params_is_valid to intel_dp_link_params_valid
* minor stylistic changes

v4:
* Compare the link rate against max link rate not the
common_rates since common_rates does not account for the
lowered fallback link rate value. (Ville Syrjala)

v5:
* Fixed a warning for unused variable (Manasi)

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491512412-30016-1-git-send-email-manasi.d.navare@intel.com

igt_mmap_offset_exhaustion() selftest was using live requests to make an
object busy, but we did not hold a runtime pm wakeref for submitting the
requests. Acquire it to avoid triggering "RPM wakelock ref not held
during HW access" warnings.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411234427.14841-3-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

If we have a mock engine and it has no more requests in flight, report
it as idle as there is no hardware to contradict us! Otherwise we
attempt to query the hw that doesn't exist and find that the hw hasn't
set its idle bit and we get upset.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411234427.14841-2-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Provide dummy function pointers for the mock device in case we do hit
mmio during testing.

v2: Use ASSIGN_READ/WRITE_MMIO_FUNCS macros
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170412092143.3822-1-chris@chris-wilson.co.uk

When discussing a new WC mmap, we based the interface upon the
assumption that GTT was fully coherent. How naive! Commits 3b5724d7
("drm/i915: Wait for writes through the GTT to land before reading
back") and ed4596ea ("drm/i915/guc: WA to address the Ringbuffer
coherency issue") demonstrate that writes through the GTT are indeed
delayed and may be overtaken by direct WC access. To be safe, if
userspace is mixing WC mmaps with other potential GTT access (pwrite,
GTT mmaps) it should use set_domain(WC).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96563
Testcase: igt/gem_pwrite/small-gtt*
Testcase: igt/drv_selftest/coherency
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170412110111.26626-2-chris@chris-wilson.co.uk

In the next patch, we will introduce a new cache domain for
differentiating between GTT access and direct WC access. This will
require us to include WC in our write_domain flushes. Rather than
duplicate a third function, combine the existing two into one and
flushing WC writes will then be automatically handled as well.

v2: Be smarter and clearer by passing in the write domains to flush (Joonas)
v3: One missed ~ in v2 conversion
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170412110111.26626-1-chris@chris-wilson.co.uk

There is no need to acquire all locks here,
doing a commit after forcing a modeset on the affected crtc
is enough. Any other locks needed will be acquired as needed.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491312297-18673-1-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit ea49c9ac.

mode_config.mutex was originally added to fix WARNs in connector
functions, but now that atomic nonblocking modeset support is
included, we will likely never hold any any lock at all.

The WARN mentioned in commit bbf35e9d ("drm/i915:
Pass atomic state to intel_audio_codec_enable, v2."), so it's
safe to revert this now.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491312168-18147-1-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No properties are supported, so just use the helper and reject everything.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491815239-10685-6-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No properties are supported, so just use the helper and reject
everything.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491815239-10685-5-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

MST doesn't support setting any properties, but it should still
use the atomic helper for setting properties.

Only path and tile properties are supported (read-only).
Those are immutable, and handled by drm core.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491815239-10685-4-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Those properties are not hooked up on MST and were ignored. Best not expose them at all.
Without this the next patch fails to start on X.org, because the DP-MST properties could
not be read.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/751b85a0-81cd-09e2-9e60-6d4ddbf1c6ac@linux.intel.com
Testcase: kms_properties
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_tv has properties that are handled in the atomic core, but
needs a modeset to update the properties inside the connector.

The detect(), get_mode() and mode_valid() probe callbacks also
depend on the connector state, which made this a good connector
to convert first. It helped find all the issues when converting
connectors to atomic.

Because of these requirements, connector atomic_check() was added
and connection_mutex is held during probing. The diffstat looks
more favorable now. :)

Changes since v1:
- Add intel_encoder->swap_state to allow updating connector state.
- Add intel_tv->format for detect_mode and mode_valid, updated on atomic commit.
Changes since v2:
- Fix typo in tv_choose_preferred modes function name.
- Assignment of tv properties is done in core, so intel_tv only needs
  a atomic_check function. Thanks Ville!
Changes since v3:
- connection_mutex is now held in mode_valid() and get_modes(),
  this removes the need for caching parts of the connector_state.
Changes since v4:
- Use the new atomic connector check function.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491815239-10685-3-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

They have been unused since 2010, after the code for
intel_tv_save/restore was removed in the below commit:

commit 6443170f
Author: Eric Anholt <eric@anholt.net>
Date:   Fri Apr 2 15:24:27 2010 -0700

    drm/i915: Remove dead KMS encoder save/restore code.

    This was brought over from UMS, and used for a while until we decided
    that drm_helper_resume_force_mode was easier and more reliable, since
    it didn't require duplicating all the code deleted here.  We just
    forgot to delete all that junk for a while.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491815239-10685-2-git-send-email-maarten.lankhorst@linux.intel.com
[mlankhorst: Add commit blurb based on danvet's feedback.]

We indirectly hold the runtime-pm for the intel_lrc_irq_handler() by
virtue of dev_priv->gt.awake keeping a wakeref whilst the requests are
busy. As this is not obvious from the code, add a comment.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411175850.2470-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Maarten needs both the new connector->atomic_check hook and the
connection_mutex locking changes in the probe helpers to be able to
start merging the connector property conversion to atomic.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Similar to commit 8490ae20 ("drm/i915: Suppress busy status for
engines if wedged") we also want to report intel_engine_is_idle() as
true as well as the main intel_engines_are_idle(), as we now check that
the engines are idle when overwriting the HWS page. This is not true
whilst we are setting the device as wedged, at least according to our
bookkeeping, so we have to lie to ourselves!

[  383.588601] [drm:i915_reset [i915]] *ERROR* Failed to reset chip: -110
[  383.588685] ------------[ cut here ]------------
[  383.588755] WARNING: CPU: 0 PID: 12 at drivers/gpu/drm/i915/intel_engine_cs.c:226 intel_engine_init_global_seqno+0x222/0x290 [i915]
[  383.588757] WARN_ON(!intel_engine_is_idle(engine))
[  383.588759] Modules linked in: ctr ccm snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core arc4 iwldvm mac80211 snd_pcm snd_hwdep snd_seq_midi snd_seq_midi_event rfcomm bnep snd_rawmidi intel_powerclamp coretemp dm_multipath iwlwifi crct10dif_pclmul snd_seq crc32_pclmul ghash_clmulni_intel btusb aesni_intel btrtl btbcm aes_x86_64 crypto_simd cryptd btintel snd_timer glue_helper bluetooth intel_ips snd_seq_device cfg80211 snd soundcore binfmt_misc mei_me mei dm_mirror dm_region_hash dm_log i915 intel_gtt i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea prime_numbers ahci libahci drm e1000e
[  383.588851] CPU: 0 PID: 12 Comm: migration/0 Not tainted 4.11.0-rc5+ #207
[  383.588853] Hardware name: LENOVO 514328U/514328U, BIOS 6QET44WW (1.14 ) 04/20/2010
[  383.588855] Call Trace:
[  383.588866]  dump_stack+0x63/0x90
[  383.588871]  __warn+0xc7/0xf0
[  383.588876]  warn_slowpath_fmt+0x4a/0x50
[  383.588883]  ? set_next_entity+0x821/0x910
[  383.588943]  intel_engine_init_global_seqno+0x222/0x290 [i915]
[  383.588998]  __i915_gem_set_wedged_BKL+0xa4/0x190 [i915]
[  383.589003]  ? __switch_to+0x215/0x390
[  383.589008]  multi_cpu_stop+0xbb/0xe0
[  383.589012]  ? cpu_stop_queue_work+0x90/0x90
[  383.589016]  cpu_stopper_thread+0x82/0x110
[  383.589021]  smpboot_thread_fn+0x137/0x190
[  383.589026]  kthread+0xf7/0x130
[  383.589030]  ? sort_range+0x20/0x20
[  383.589034]  ? kthread_park+0x90/0x90
[  383.589040]  ret_from_fork+0x2c/0x40

Fixes: 2ca9faa5 ("drm/i915: Assert the engine is idle before overwiting the HWS")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411190042.25662-1-chris@chris-wilson.co.uk

Technically speaking, the context size is per engine class, not per
instance.

v2: Add MISSING_CASE (Tvrtko)

v3: Rebased

v4: Restore the interface back to hiding the class lookup (Chris)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491905472-16189-1-git-send-email-oscar.mateo@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In places, we assume that RCS exists. This has been true forever, but
let us catch this failure during bringup by adding an explicit check
that we do have an RCS engine.

v2: Make use of HAS_ENGINE (Tvrtko)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411165658.23828-1-chris@chris-wilson.co.uk

Don't clobber intel_dp->sink_count with the raw value.
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/37d3222115172922fcd5ab038238359935bd561f.1491485983.git.jani.nikula@intel.com

This is what we have the readb and writeb variants for. Do some minor
return value and variable cleanup while at it.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/fd8a8f110bcfdc73a8c9241e5f9d61f7dd7c9677.1491485983.git.jani.nikula@intel.com

Localize link_rate_index to the if block, and rename to just index to
reduce indent.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/d348d990c96705427b93c1cac8c3e4447d06eebf.1491485983.git.jani.nikula@intel.com

The source might not support as many lanes as the sink, or the link
training might have failed at higher lane counts. Take these into
account.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/cf59530acafaf9258fb643d321ad251b44f34e29.1491485983.git.jani.nikula@intel.com

These are the theoretical maximums common for source and sink. These are
the maximums we should start with. They may be degraded in case of link
training failures, and the dynamic link values are stored separately.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/5088aca253c47dfa18251e1adb976aca1718f083.1491485983.git.jani.nikula@intel.com

If we modify these on the fly depending on the link conditions, don't
pretend they are sink properties.

Some link vs. sink confusion still remains, but we'll take care of them
in follow-up patches.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/3739b4fac502ebd1c6e075a62c1a195e4094eb16.1491485983.git.jani.nikula@intel.com

In link training fallback, we're trying to find a rate that we know is
in a sorted array of common link rates. We don't need to limit the array
using the max rate. For test request, the DP CTS doesn't say we should
limit the rate based on earlier fallback. This lets us get rid of
intel_dp_link_rate_index() and use intel_dp_rate_index() instead.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/33cab481a3228f31e938b5891a6285d892dcf272.1491485983.git.jani.nikula@intel.com

Now that source rates are static and sink rates are updated whenever
DPCD is updated, we can do and cache the intersection of them whenever
sink rates are updated. This reduces code complexity, as we don't have
to keep calling the functions to intersect. We also get rid of several
common rates arrays on stack.

Limiting the common rates by a max link rate can be done by picking the
first N elements of the cached common rates.

v2: get rid of the local common_rates variable (Manasi)
v3: don't clobber cached eDP rates on short pulse (Ville)

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/e3b287e8cb6559b1f8fd4e80b78a8d22f1802eb7.1491485983.git.jani.nikula@intel.com

Looking at DPCD DP_MAX_LINK_RATE may be completely bogus for eDP 1.4
which is allowed to use link rate select method and have 0 in max link
rate. With this change, it makes sense to store the max rate as the
actual rate rather than as a bw code.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/3e8baadb406d59f414cab36fed9f0b35d207fde5.1491485983.git.jani.nikula@intel.com

We want to refer to the index of the engine consistently throughout the
userspace ABI. We already have such an index through the execbuffer
engine specifier, that needs to be able to refer to each engine
specifically, so rename it the index to uabi_id to reflect its
generality beyond execbuf.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411124306.15448-1-chris@chris-wilson.co.uk

There are some properties that logically belong to the engine class, and some
that belong to the engine instance. Make it explicit.

v2: Commit message (Tvrtko)

v3:
  - Rebased
  - Exec/uabi id should be per instance (Chris)

v4:
  - Rebased
  - Avoid re-ordering fields for smaller diff (Tvrtko)
  - Bug on oob access to the class array (Michal)

v5: Bug on the right thing (Michal)

v6: Rebased

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-5-git-send-email-oscar.mateo@intel.comReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Not really needed, but makes the next change a little bit more compact.

v2:
  - Use zero-based numbering for engine names: xcs0, xcs1.. xcsN (Tvrtko, Chris)
  - Make sure the mock engine name is null-terminated (Tvrtko, Chris)

v3: Because I'm stupid (Chris)

v4: Verify engine name wasn't truncated (Michal)

v5:
  - Kill the warning in mock engine (Chris)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-4-git-send-email-oscar.mateo@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

If we needed to do something different for the init functions, we could
always look at the engine instance to make the distinction. But, in any
case, the two functions are virtually identical already (please notice
that BSD2_RING is only used from gen8 onwards).

With this, the init functions depends excusively on the engine class
(a fact that we will use soon).

v2: Commit message

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-3-git-send-email-oscar.mateo@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In such a way that vcs and vcs2 are just two different instances (0 and 1)
of the same engine class (VIDEO_DECODE_CLASS).

v2: Align the instance types (Tvrtko)

v3: Don't use enums for bspec-defined stuff (Michal)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-2-git-send-email-oscar.mateo@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

While we do hold the forcewake for legacy ringbuffer initialisation, we
don't guard our access with the uncore.lock spinlock. In theory, we only
initialise when no others should be accessing the same mmio cachelines,
but in practice be safe as this is an infrequently used path and not
worth risky micro-optimisations.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411101340.31994-5-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Since the sandybridge_pcode_read() may be called from
skl_pcode_request() inside an atomic context (with preempt disabled), we
should avoid hitting any sleeping paths. Currently is being called with
a 500ms timeout, irrespective of being inside an atomic context or not.
This is reduced down to 500us to play nice with the atomic context, and
that appears to be sufficient to keep BAT happy (we have a DRM_ERROR
should it timeout), i.e. we do not see any 500us pcode timeouts for
normal use. So leave it as a pure spin without having to introduce new
code paths to separate atomic/normal contexts.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411101340.31994-4-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>