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:

- 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.

Fixes: fdo#93147
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Michel Dänzer <michel.daenzer@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>

(v1) Tested-by: Dave Witbrodt <dawitbro@sbcglobal.net>

(v2) Refine radeon_flip_work_func() for better efficiency:

     In radeon_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.

     Retested on DCE-3 and DCE-4 to verify it still works nicely.

(v2) Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

DP audio is derived from the dfs clock.
Signed-off-by: Slava Grigorev <slava.grigorev@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

This avoids allocating it on the fly.

v2: fix grammar in comment
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>

This way we avoid the extra allocation for the page directory entry.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>

They share the reservation object with the page directory anyway.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
CC: stable@vger.kernel.org

In some cases the amount of vram may be less than the BAR size,
if so, limit visible vram to the amount of actual vram, not the
BAR size.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Change the default scheduler queue size from 16 to 32.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Properly handle ctx init failure.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

umd somtimes will create a context for every ring,
that means some entities wouldn't be used at all.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Add more fine grained debugging output for init/fini/suspend/
resume failures.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Change-Id: I2ae9bb4a929f7c0c8783e0be563ae04be77596e2
Signed-off-by: Flora Cui <Flora.Cui@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Use default value as a base.
Signed-off-by: Flora Cui <Flora.Cui@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

Otherwise FW cannot see the RLC ACK for the memory clean request
It's for Stoney.
Signed-off-by: Flora Cui <Flora.Cui@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

there is a protection fault about freed list when OCL test.
add a spin lock to protect it.

v2: drop changes in vm_fini
Signed-off-by: JimQu <jim.qu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

As soon as we leave the spinlock after the job has been added to the job
queue, we can no longer rely on the job's data to be available.

I have seen a null-pointer dereference due to sched == NULL in
amd_sched_wakeup via amd_sched_entity_push_job and
amd_sched_ib_submit_kernel_helper. Since the latter initializes
sched_job->sched with the address of the ring scheduler, which is
guaranteed to be non-NULL, this race appears to be a likely culprit.
Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Bugzilla: https://bugs.freedesktop.org/attachment.cgi?bugid=93079Reviewed-by: Christian König <christian.koenig@amd.com>

Missing error check if the operation failed.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

Simplified the function by folding the two paths into one.
Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Simplification of the function gfx_v8_0_create_bitmask().
Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Simplification and LOC reduction of function gfx_v8_0_tiling_mode_table_init()

v2: remove spurious break
bug: https://bugs.freedesktop.org/show_bug.cgi?id=93236Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

Allows us to set priorities in the scheduler.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>

This adds EDC support for CZ.
EDC = Error Correction and Detection
This code properly initializes the EDC hardware and
resets the error counts.  This is done in late_init
since it requires the IB pool which is not initialized
during hw_init.

v2: fix the IB size as noted by Felix, fix shader pgm
register programming
v3: use the IB for the shaders as suggested by Christian
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

EDC is a RAS feature for on chip memory.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

For drm_gem_object_unreference callers are required to hold
dev->struct_mutex, which these paths don't. Enforcing this requirement
has become a bit more strict with

commit ef4c6270
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Oct 15 09:36:25 2015 +0200

    drm/gem: Check locking in drm_gem_object_unreference

Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

For drm_gem_object_unreference callers are required to hold
dev->struct_mutex, which these paths don't. Enforcing this requirement
has become a bit more strict with

commit ef4c6270
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Oct 15 09:36:25 2015 +0200

    drm/gem: Check locking in drm_gem_object_unreference

Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Read the vbios directly from the rom.  In some cases,
e.g., virtualization, the rom is not available via
the BAR or other means.  Access it directly.

This is an updated version of Monks original patch which
uses family specific callbacks and unifies some of the
validation checking.
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Read the vbios image directly from the rom.
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Read the vbios image directly from the rom.
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

This is necessary when the vbios image is not directly accessible via
the rom BAR or legacy vga location.
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

The radeon_asic_ring structures are never modified, so declare them as
const.

Done with the help of Coccinelle.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

This can solve the path problem when compile amdgpu with DKMS.

v2: agd: rebase on current drm-next
Signed-off-by: Jammy Zhou <Jammy.Zhou@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Need to call this on resume if displays changes during
suspend in order to properly be notified of changes.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Need to call this on resume if displays changes during
suspend in order to properly be notified of changes.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

It's been deprecated behind a kconfig option for almost
two years and hasn't really been supported for years before
that.  DDX support was dropped more than three years ago.
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Merge tag 'drm-intel-next-2015-11-20-merged' of git://anongit.freedesktop.org/drm-intel into drm-next

drm-intel-next-2015-11-20-rebased:
4 weeks because of my vacation, so a bit more:
- final bits of the typesafe register mmio functions (Ville)
- power domain fix for hdmi detection (Imre)
- tons of fixes and improvements to the psr code (Rodrigo)
- refactoring of the dp detection code (Ander)
- complete rework of the dmc loader and dc5/dc6 handling (Imre, Patrik and
  others)
- dp compliance improvements from Shubhangi Shrivastava
- stop_machine hack from Chris to fix corruptions when updating GTT ptes on bsw
- lots of fifo underrun fixes from Ville
- big pile of fbc fixes and improvements from Paulo
- fix fbdev failures paths (Tvrtko and Lukas Wunner)
- dp link training refactoring (Ander)
- interruptible prepare_plane for atomic (Maarten)
- basic kabylake support (Deepak&Rodrigo)
- don't leak ringspace on resets (Chris)
drm-intel-next-2015-10-23:
- 2nd attempt at atomic watermarks from Matt, but just prep for now
- fixes all over

* tag 'drm-intel-next-2015-11-20-merged' of git://anongit.freedesktop.org/drm-intel: (209 commits)
  drm/i915: Update DRIVER_DATE to 20151120
  drm/i915: take a power domain reference while checking the HDMI live status
  drm/i915: take a power domain ref only when needed during HDMI detect
  drm/i915: Tear down fbdev if initialization fails
  async: export current_is_async()
  Revert "drm/i915: Initialize HWS page address after GPU reset"
  drm/i915: Fix oops caused by fbdev initialization failure
  drm/i915: Fix i915_ggtt_view_equal to handle rotation correctly
  drm/i915: Stuff rotation params into view union
  drm/i915: Drop return value from intel_fill_fb_ggtt_view
  drm/i915 : Fix to remove unnecsessary checks in postclose function.
  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: Remove platform specific *_dp_detect() functions
  drm/i915: Don't do edp panel detection in g4x_dp_detect()
  drm/i915: Send TP1 TP2/3 even when panel claims no NO_TRAIN_ON_EXIT.
  drm/i915: PSR: Don't Skip aux handshake on DP_PSR_NO_TRAIN_ON_EXIT.
  drm/i915: Reduce PSR re-activation time for VLV/CHV.
  drm/i915: Delay first PSR activation.
  drm/i915: Type safe register read/write
  ...

Here's the first drm-misc pull, with really mostly misc stuff all over.
Somewhat invasive is only Ville's change to mark the arg struct for
fb_create const - that might conflict with a new driver pull. So better to
get in fast.

* tag 'topic/drm-misc-2015-11-26' of git://anongit.freedesktop.org/drm-intel:
  drm/mm: use list_next_entry
  drm/i915: fix potential dangling else problems in for_each_ macros
  drm: fix potential dangling else problems in for_each_ macros
  drm/sysfs: Send out uevent when connector->force changes
  drm/atomic: Small documentation fix.
  drm/mm: rewrite drm_mm_for_each_hole
  drm/sysfs: Grab lock for edid/modes_show
  drm: Print the src/dst/clip rectangles in error in drm_plane_helper
  drm: Add "prefix" parameter to drm_rect_debug_print()
  drm: Keep coordinates in the typical x, y, w, h order instead of x, y, h, w
  drm: Pass the user drm_mode_fb_cmd2 as const to .fb_create()
  drm: modes: replace simple_strtoul by kstrtouint
  drm: Describe the Rotation property bits.
  drm: Remove unused fbdev_list members
  GPU-DRM: Delete unnecessary checks before drm_property_unreference_blob()
  drm/dp: add eDP DPCD backlight control bit definitions
  drm/tegra: Remove local fbdev emulation Kconfig option
  drm/imx: Remove local fbdev emulation Kconfig option
  drm/gem: Update/Polish docs
  drm: Update GEM refcounting docs