The meat here is definitely the detailed specs for what atomic_check
and atomic_commit are supposed to do.

And another candidate for a core vfunc that should be in a helper really
(output_poll_changed this time around).

v2: Feedback from Eric on irc:
- spelling fixes.
- spec what async should do
- copy the event related paragraphs from page_flip and adjust
- make it clear that a successful async commit is not allowed to leave
  the pipe dead or disabled.

v3: Use FIXME comments to annotate functions that we should move to
some helpers.

v4: Suggestions from Thierry.

Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-22-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

While typing these I noticed that ->dirty is a bit a can of worms
and even supports blt/fill semantics ... shocked me a bit.

Oh well it's defined in a way that nothing bad (just a bit of inefficiency)
will happen for drivers which supports this. So I didn't bother copying
the detailed spec into the new kerneldoc.

v2: Suggestions from Thierry.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-21-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

And merge any docbook we have into the kerneldoc comments.

Since it's a legacy entry point with only two implementation (one each
in atomic and legacy crtc helpers) I've made the documentation for
set_config fairly sparse - no one should ever need to look at this
again, all the ABI we have is baked into code.

For ->page_flip otoh I kept all the extensive docs from the docbook
and even extended it where it was lacking: Currently we have a pile of
legacy page_flip implemantations, and even for atomic drivers there's
not yet a standard implementation in the helpers. Which means every
driver needs to implement this itself, and precise specs are really
valuable.

Otherwise there's just cursor, which really just boils down to "use at
least universal planes". And gamma tables (where we have a bit a mess
with the fbdev helper gamma hooks).

v2: Spelling fixes (Eric).

v3: Suggestions from Thierry.

Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-20-git-send-email-daniel.vetter@ffwll.ch

We always register the DPMS property, it's really a fundamental
part of a display driver. So don't check whether the vfunc is there,
it's non-optional

Yes I've audited all the almost 100 drm_connector_funcs we have, no
one botched this ;-)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-19-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

The special case here is that both ->detect and ->force are actually
functions only called by the probe helpers and hence really shouldn't
be here. But since they've used by pretty much every driver I figured
it's better to just document this for now instead of holding this doc
patch hostage until that's all fixed. For that reason also group force
right next to detect.

v2: Use FIXME comments to annotate where we should move a hook to
helpers.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-18-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

Yes these are internal functions and not exported and we generally
don't document them. But for symmetry with the _set_property functions
(which are exported for the atomic helpers) I'd like to document them.
Upcoming vtable kerneldoc will reference both the set and get_property
functions.

v2: Suggestions from Thierry.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-17-git-send-email-daniel.vetter@ffwll.ch

Nouveau is the only user, and atomic drivers should do state
save/restoring differently. So move it into noveau.

Saves me typing some kerneldoc, too ;-)

v2: Move misplaced hunk into earlier nouveau patch.

Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449245647-1315-1-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

They're not how system suspend/resume should be done with atomic
(there's new helpers for that developed by Thierry Reding), and for
legacy drivers this really should be a helper hook and not a core one.

But there's not even helper code to use them, and only 2 drivers
(which now have their own private hooks) set them. Ditch them.

Saves me typing some kerneldoc, too ;-)
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-15-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

I want to remove the core ones since with atomic drivers system
suspend/resume is solved much differently. And there's only 2 drivers
(gma500 besides nouveau) really using them.

v2: Fixup bugs Ilia spotted.

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449245618-1127-1-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

I want to remove the core ones since with atomic drivers system
suspend/resume is solved much differently. And there's only 2 drivers
(nouveau besides gma500) really using them.

v2: Fixup build noise 0day reported.

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-13-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Thierry Reding <treding@nvidia.com> (v1)

save/restore have been removed from drm_encoder_helper_funcs by
'commit 79f13ad5d8e0 ("drm: Move encoder->save/restore into nouveau")'

But this module was still defining it with empty content causing
compilation fails:

drivers/gpu/drm/i2c/tda998x_drv.c:1354:10: warning: initialization from
incompatible pointer type [-Wincompatible-pointer-types]
  .save = tda998x_encoder_save,

drivers/gpu/drm/i2c/tda998x_drv.c:1355:2: error: unknown field 'restore'
specified in initializer
  .restore = tda998x_encoder_restore,

Cc: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449513306-17309-1-git-send-email-rodrigo.vivi@intel.com

These hooks will be gone soon.

Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-12-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

These hooks will be gone soon.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-11-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

These hooks will be gone soon.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-10-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

gcc does this for us, and these hooks will be gone soon.

Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-9-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

- Merge the docbook into the kerneldoc comments.

- Spec in detail the precise semantics of the callbacks.

- For consistency in wording and easier review roll out kerneldoc also
  for crtc, encoder and connector for the standard hooks they share
  with planes.

v2: Suggestions from Thierry.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-8-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

Especially document the assumptions and semantics of the callbacks
carefully. Just a warm-up excercise really.

v2: Spelling fixes (Eric).

v3: Consolidate more with existing docs:

- Remove the overview section explaining the bridge funcs, that's
  now all in the drm_bridge_funcs kerneldoc in much more detail.

- Use & to reference structs so that kerneldoc automatically inserts
  hyperlinks.

v4: Review from Thierry.

Cc: Eric Anholt <eric@anholt.net>
Cc: Archit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Archit Taneja <architt@codeaurora.org> (v3)
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-7-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

Duplication is bad, luckily both help texts highlighted different
issues so the kerneldoc gained quite a bit!

While at it also sprinkle more references to the vtable structs around
and make it clear that legacy CRTC helpers are deprecated and which
functions to use instead.

v2: Spelling fixes and polish (Thierry).
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-6-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

Originally the idea behind void* was to allow different sets of
helpers. But now we have that (with probe, plane, crtc and atomic
helpers) and we still just use the same set of vtables. That's the
only way to make the individual helpers modular and allow drivers to
pick&choose and transition between them. So this flexibility isn't
really needed. Also we have lots of non-vtable data meanwhile in core
structures too, this is not the first one at all.

Given that the void * is only trouble since gcc can't warn you if you
mix them up. Let's fix that and make them typesafe.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-5-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

Currently we have 4 helper libraries (probe, crtc, plane & atomic)
that all use the same helper vtables. And that's by necessity since we
don't want to litter the core structs with one ops pointer per helper
library. Also often the reuse the same hooks (like atomic does, to
facilite conversion from existing drivers using crtc and plane
helpers).

Given all that it doesn't make sense to put the docs for these next to
specific helpers. Instead extract them into a new header file and
section in the docbook, and add references to them everywhere.

Unfortunately kernel-doc complains when an include directive doesn't
find anything (and it does by dumping crap into the output file). We
have to remove the now empty includes to avoid that, instead of leaving
them in for future proofing.

v2: More OCD in ordering functions.

v3: Spelling plus collate copyright headers properly.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-4-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

This is only used for kgdb (and previously panic) handlers in
the fbdev emulation, so belongs there.

Note that this means we'll leave behind a forward declaration, but
once all the helper vtables are consolidated (in the next patch) that
will make more sense.

v2: fixup radone/amdgpu.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-3-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Thierry Reding <treding@nvidia.com> (v2)

Mostly this is just adding extensive docs for the callbacks, but also
a few other additions.

v2: Use FIXME comments to annotate helper hooks that should be
replaced.

v3: Small nits (Thierry).
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-2-git-send-email-daniel.vetter@ffwll.chReviewed-by: NThierry Reding <treding@nvidia.com>

We've picked up a few conflicts and it would be nice
to resolve them before we move onwards.

New -misc pull. Big thing is Thierry's atomic helpers for system suspend
resume, which I'd like to use in i915 too. Hence the pull.

* tag 'topic/drm-misc-2015-12-04' of git://anongit.freedesktop.org/drm-intel:
  drm: keep connector status change logging human readable
  drm/atomic-helper: Reject attempts at re-stealing encoders
  drm/atomic-helper: Implement subsystem-level suspend/resume
  drm: Implement drm_modeset_lock_all_ctx()
  drm/gma500: Add driver private mutex for the fault handler
  drm/gma500: Drop dev->struct_mutex from mmap offset function
  drm/gma500: Drop dev->struct_mutex from fbdev init/teardown code
  drm/gma500: Drop dev->struct_mutex from modeset code
  drm/gma500: Use correct unref in the gem bo create function
  drm/edid: Make the detailed timing CEA/HDMI mode fixup accept up to 5kHz clock difference
  drm/atomic_helper: Add drm_atomic_helper_disable_planes_on_crtc()
  drm: Serialise multiple event readers
  drm: Drop dev->event_lock spinlock around faulting copy_to_user()

The ioctl IOC_LIBCFS_PING_TEST has not been used in ages.  The recent
nidstring changes which moved all the nidstring operations from libcfs
to the LNet layer but this ioctl code was still using an nidstring
operation that was causing a circular dependency loop between libcfs and
LNet.
Signed-off-by: NJames Simmons <jsimmons@infradead.org>
Signed-off-by: NOleg Drokin <green@linuxhacker.ru>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull vfs fixes from Al Viro:
 "A couple of fixes (-stable fodder) + dead code removal after the
  overlayfs fix.

  I agree that it's better to separate from the fix part to make
  backporting easier, but IMO it's not worth delaying said dead code
  removal until the next window"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Don't reset ->total_link_count on nested calls of vfs_path_lookup()
  ovl: get rid of the dead code left from broken (and disabled) optimizations
  ovl: fix permission checking for setattr

we already zero it on outermost set_nameidata(), so initialization in
path_init() is pointless and wrong.  The same DoS exists on pre-4.2
kernels, but there a slightly different fix will be needed.

Cc: stable@vger.kernel.org # v4.2
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

[Al Viro] The bug is in being too enthusiastic about optimizing ->setattr()
away - instead of "copy verbatim with metadata" + "chmod/chown/utimes"
(with the former being always safe and the latter failing in case of
insufficient permissions) it tries to combine these two.  Note that copyup
itself will have to do ->setattr() anyway; _that_ is where the elevated
capabilities are right.  Having these two ->setattr() (one to set verbatim
copy of metadata, another to do what overlayfs ->setattr() had been asked
to do in the first place) combined is where it breaks.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull scheduler fixes from Thomas Gleixner:
 "This updates contains the following changes:

   - Fix a signal handling regression in the bit wait functions.

   - Avoid false positive warnings in the wakeup path.

   - Initialize the scheduler root domain properly.

   - Handle gtime calculations in proc/$PID/stat proper.

   - Add more documentation for the barriers in try_to_wake_up().

   - Fix a subtle race in try_to_wake_up() which might cause a task to
     be scheduled on two cpus

   - Compile static helper function only when it is used"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Fix an SMP ordering race in try_to_wake_up() vs. schedule()
  sched/core: Better document the try_to_wake_up() barriers
  sched/cputime: Fix invalid gtime in proc
  sched/core: Clear the root_domain cpumasks in init_rootdomain()
  sched/core: Remove false-positive warning from wake_up_process()
  sched/wait: Fix signal handling in bit wait helpers
  sched/rt: Hide the push_irq_work_func() declaration

Pull x86 fixes from Thoma Gleixner:
 "Another round of fixes for x86:

   - Move the initialization of the microcode driver to late_initcall to
     make sure everything that init function needs is available.

   - Make sure that lockdep knows about interrupts being off in the
     entry code before calling into c-code.

   - Undo the cpu hotplug init delay regression.

   - Use the proper conditionals in the mpx instruction decoder.

   - Fixup restart_syscall for x32 tasks.

   - Fix the hugepage regression on PAE kernels which was introduced
     with the latest PAT changes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/signal: Fix restart_syscall number for x32 tasks
  x86/mpx: Fix instruction decoder condition
  x86/mm: Fix regression with huge pages on PAE
  x86 smpboot: Re-enable init_udelay=0 by default on modern CPUs
  x86/entry/64: Fix irqflag tracing wrt context tracking
  x86/microcode: Initialize the driver late when facilities are up

Pull SCSI fixes from James Bottomley:
 "This is quite a bumper crop of fixes: three from Arnd correcting
  various build issues in some configurations, a lock recursion in
  qla2xxx.  Two potentially exploitable issues in hpsa and mvsas, a
  potential null deref in st, a revert of a bdi registration fix that
  turned out to cause even more problems, a set of fixes to allow people
  who only defined MPT2SAS to still work after the mpt2/mpt3sas merger
  and a couple of fixes for issues turned up by the hyper-v storvsc
  driver"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  mpt3sas: fix Kconfig dependency problem for mpt2sas back compatibility
  Revert "scsi: Fix a bdi reregistration race"
  mpt3sas: Add dummy Kconfig option for backwards compatibility
  Fix a memory leak in scsi_host_dev_release()
  block/sd: Fix device-imposed transfer length limits
  scsi_debug: fix prevent_allow+verify regressions
  MAINTAINERS: Add myself as co-maintainer of the SCSI subsystem.
  sd: Make discard granularity match logical block size when LBPRZ=1
  scsi: hpsa: select CONFIG_SCSI_SAS_ATTR
  scsi: advansys needs ISA dma api for ISA support
  scsi_sysfs: protect against double execution of __scsi_remove_device()
  st: fix potential null pointer dereference.
  scsi: report 'INQUIRY result too short' once per host
  advansys: fix big-endian builds
  qla2xxx: Fix rwlock recursion
  hpsa: logical vs bitwise AND typo
  mvsas: don't allow negative timeouts
  mpt3sas: Fix use sas_is_tlr_enabled API before enabling MPI2_SCSIIO_CONTROL_TLR_ON flag

Pull drm fixes from Dave Airlie:
 "A bunch of change across the board, the main things are some vblank
  fallout in radeon and nouveau required some work, but I think this
  should fix it all.  There is also one drm fix for an oops in vmwgfx
  with how we pass the drm master around.

  The rest is just some amdgpu, i915, imx and rockchip fixes.

  Probably more than I'd like at this point, but hopefully things settle
  down now"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (40 commits)
  drm/amdgpu: Fixup hw vblank counter/ts for new drm_update_vblank_count() (v3)
  drm/radeon: Fixup hw vblank counter/ts for new drm_update_vblank_count() (v2)
  drm/radeon: Retry DDC probing on DVI on failure if we got an HPD interrupt
  drm/amdgpu: add spin lock to protect freed list in vm (v2)
  drm/amdgpu: partially revert "drm/amdgpu: fix VM_CONTEXT*_PAGE_TABLE_END_ADDR" v2
  drm/amdgpu: take a BO reference for the user fence
  drm/amdgpu: take a BO reference in the display code
  drm/amdgpu: set snooped flags only on system addresses v2
  drm/nouveau: Fix pre-nv50 pageflip events (v4)
  drm: Fix an unwanted master inheritance v2
  drm/amdgpu: fix race condition in amd_sched_entity_push_job
  drm/amdgpu: add err check for pin userptr
  drm/i915: take a power domain reference while checking the HDMI live status
  drm/i915: add MISSING_CASE to a few port/aux power domain helpers
  drm/i915/ddi: fix intel_display_port_aux_power_domain() after HDMI detect
  drm/i915: Introduce a gmbus power domain
  drm/i915: Clean up AUX power domain handling
  drm/rockchip: Use CRTC vblank event interface
  drm/rockchip: Fix module autoload for OF platform driver
  drm/rockchip: vop: fix window origin calculation
  ...

Pull crypto fixes from Herbert Xu:
 "This fixes a couple of crypto drivers that were using memcmp to verify
  authentication tags.  They now use crypto_memneq instead"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: talitos - Fix timing leak in ESP ICV verification
  crypto: nx - Fix timing leak in GCM and CCM decryption

When restarting a syscall with regs->ax == -ERESTART_RESTARTBLOCK,
regs->ax is assigned to a restart_syscall number.  For x32 tasks, this
syscall number must have __X32_SYSCALL_BIT set, otherwise it will be
an x86_64 syscall number instead of a valid x32 syscall number. This
issue has been there since the introduction of x32.

Reported-by: strace/tests/restart_syscall.test
Reported-and-tested-by: NElvira Khabirova <lineprinter0@gmail.com>
Signed-off-by: NDmitry V. Levin <ldv@altlinux.org>
Cc: Elvira Khabirova <lineprinter0@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20151130215436.GA25996@altlinux.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

MPX decodes instructions in order to tell which bounds register
was violated.  Part of this decoding involves looking at the "REX
prefix" which is a special instrucion prefix used to retrofit
support for new registers in to old instructions.

The X86_REX_*() macros are defined to return actual bit values:

	#define X86_REX_R(rex) ((rex) & 4)

*not* boolean values.  However, the MPX code was checking for
them like they were booleans.  This might have led to us
mis-decoding the "REX prefix" and giving false information out to
userspace about bounds violations.  X86_REX_B() actually is bit 1,
so this is really only broken for the X86_REX_X() case.

Fix the conditionals up to tolerate the non-boolean values.

Fixes: fcc7ffd6 "x86, mpx: Decode MPX instruction to get bound violation information"
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20151201003113.D800C1E0@viggo.jf.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

A few more last minute fixes for 4.4 on top of my pull request from
earlier this week.  The big change here is a vblank regression fix due to
commit 4dfd6486 "drm: Use vblank timestamps to guesstimate how many vblanks
were missed".  Beyond that, a hotplug fix and a few VM fixes.

* 'drm-fixes-4.4' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: Fixup hw vblank counter/ts for new drm_update_vblank_count() (v3)
  drm/radeon: Fixup hw vblank counter/ts for new drm_update_vblank_count() (v2)
  drm/radeon: Retry DDC probing on DVI on failure if we got an HPD interrupt
  drm/amdgpu: add spin lock to protect freed list in vm (v2)
  drm/amdgpu: partially revert "drm/amdgpu: fix VM_CONTEXT*_PAGE_TABLE_END_ADDR" v2
  drm/amdgpu: take a BO reference for the user fence
  drm/amdgpu: take a BO reference in the display code
  drm/amdgpu: set snooped flags only on system addresses v2
  drm/amdgpu: fix race condition in amd_sched_entity_push_job
  drm/amdgpu: add err check for pin userptr
  add blacklist for thinkpad T40p
  drm/amdgpu: fix VM page table reference counting
  drm/amdgpu: fix userptr flags check

Pull Ceph fix from Sage Weil:
 "This addresses a refcounting bug that leads to a use-after-free"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: don't put snap_context twice in rbd_queue_workfn()

commit 4dfd6486 "drm: Use vblank timestamps to guesstimate how many
vblanks were missed" introduced in Linux 4.4-rc1 makes the drm core
more fragile to drivers which don't update hw vblank counters and
vblank timestamps in sync with firing of the vblank irq and
essentially at leading edge of vblank.

This exposed a problem with radeon-kms/amdgpu-kms which do not
satisfy above requirements:

The vblank irq fires a few scanlines before start of vblank, but
programmed pageflips complete at start of vblank and
vblank timestamps update at start of vblank, whereas the
hw vblank counter increments only later, at start of vsync.

This leads to problems like off by one errors for vblank counter
updates, vblank counters apparently going backwards or vblank
timestamps apparently having time going backwards. The net result
is stuttering of graphics in games, or little hangs, as well as
total failure of timing sensitive applications.

See bug #93147 for an example of the regression on Linux 4.4-rc:

https://bugs.freedesktop.org/show_bug.cgi?id=93147

This patch tries to align all above events better from the
viewpoint of the drm core / of external callers to fix the problem:

1. The apparent start of vblank is shifted a few scanlines earlier,
so the vblank irq now always happens after start of this extended
vblank interval and thereby drm_update_vblank_count() always samples
the updated vblank count and timestamp of the new vblank interval.

To achieve this, the reporting of scanout positions by
radeon_get_crtc_scanoutpos() now operates as if the vblank starts
radeon_crtc->lb_vblank_lead_lines before the real start of the hw
vblank interval. This means that the vblank timestamps which are based
on these scanout positions will now update at this earlier start of
vblank.

2. The driver->get_vblank_counter() function will bump the returned
vblank count as read from the hw by +1 if the query happens after
the shifted earlier start of the vblank, but before the real hw increment
at start of vsync, so the counter appears to increment at start of vblank
in sync with the timestamp update.

3. Calls from vblank irq-context and regular non-irq calls are now
treated identical, always simulating the shifted vblank start, to
avoid inconsistent results for queries happening from vblank irq vs.
happening from drm_vblank_enable() or vblank_disable_fn().

4. The radeon_flip_work_func will delay mmio programming a pageflip until
the start of the real vblank iff it happens to execute inside the shifted
earlier start of the vblank, so pageflips now also appear to execute at
start of the shifted vblank, in sync with vblank counter and timestamp
updates. This to avoid some races between updates of vblank count and
timestamps that are used for swap scheduling and pageflip execution which
could cause pageflips to execute before the scheduled target vblank.

The lb_vblank_lead_lines "fudge" value is calculated as the size of
the display controllers line buffer in scanlines for the given video
mode: Vblank irq's are triggered by the line buffer logic when the line
buffer refill for a video frame ends, ie. when the line buffer source read
position enters the hw vblank. This means that a vblank irq could fire at
most as many scanlines before the current reported scanout position of the
crtc timing generator as the number of scanlines the line buffer can
maximally hold for a given video mode.

This patch has been successfully tested on a RV730 card with DCE-3 display
engine and on a evergreen card with DCE-4 display engine, in single-display
and dual-display configuration, with different video modes.

A similar patch is needed for amdgpu-kms to fix the same problem.

Limitations:

- Maybe replace the udelay() in the flip_work_func() by a suitable
  usleep_range() for a bit better efficiency? Will try that.

- Line buffer sizes in pixels are hard-coded on < DCE-4 to a value
  i just guessed to be high enough to work ok, lacking info on the true
  sizes atm.

Probably fixes: fdo#93147

Port of Mario's radeon fix to amdgpu.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
(v1) Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com>

(v2) Refine amdgpu_flip_work_func() for better efficiency.

     In amdgpu_flip_work_func, replace the busy waiting udelay(5)
     with event lock held by a more performance and energy efficient
     usleep_range() until at least predicted true start of hw vblank,
     with some slack for scheduler happiness. Release the event lock
     during waits to not delay other outputs in doing their stuff, as
     the waiting can last up to 200 usecs in some cases.

     Also small fix to code comment and formatting in that function.

(v2) Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>

(v3) Fix crash in crtc disabled case