Commit Graph

10256 Commits

Author SHA1 Message Date
Maarten Lankhorst
2fde13910c drm/i915: Use passed plane state for sprite planes, v4.
Don't use plane->state directly, use the pointer from commit_plane.

Changes since v1:
- Fix uses of plane->state->rotation and color key to use the passed state too.
- Only pass crtc_state and plane_state to update_plane.
Changes since v2:
- Rebased.
Changes since v3:
- Small whitespace changes and only assign 1 variable per line.
- Constify plane_state and crtc_state. (vsyrjala)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452164052-21752-2-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
2016-01-07 13:50:02 +01:00
Matt Roper
396e33ae20 drm/i915: Add two-stage ILK-style watermark programming (v10)
In addition to calculating final watermarks, let's also pre-calculate a
set of intermediate watermark values at atomic check time.  These
intermediate watermarks are a combination of the watermarks for the old
state and the new state; they should satisfy the requirements of both
states which means they can be programmed immediately when we commit the
atomic state (without waiting for a vblank).  Once the vblank does
happen, we can then re-program watermarks to the more optimal final
value.

v2: Significant rebasing/rewriting.

v3:
 - Move 'need_postvbl_update' flag to CRTC state (Daniel)
 - Don't forget to check intermediate watermark values for validity
   (Maarten)
 - Don't due async watermark optimization; just do it at the end of the
   atomic transaction, after waiting for vblanks.  We do want it to be
   async eventually, but adding that now will cause more trouble for
   Maarten's in-progress work.  (Maarten)
 - Don't allocate space in crtc_state for intermediate watermarks on
   platforms that don't need it (gen9+).
 - Move WaCxSRDisabledForSpriteScaling:ivb into intel_begin_crtc_commit
   now that ilk_update_wm is gone.

v4:
 - Add a wm_mutex to cover updates to intel_crtc->active and the
   need_postvbl_update flag.  Since we don't have async yet it isn't
   terribly important yet, but might as well add it now.
 - Change interface to program watermarks.  Platforms will now expose
   .initial_watermarks() and .optimize_watermarks() functions to do
   watermark programming.  These should lock wm_mutex, copy the
   appropriate state values into intel_crtc->active, and then call
   the internal program watermarks function.

v5:
 - Skip intermediate watermark calculation/check during initial hardware
   readout since we don't trust the existing HW values (and don't have
   valid values of our own yet).
 - Don't try to call .optimize_watermarks() on platforms that don't have
   atomic watermarks yet.  (Maarten)

v6:
 - Rebase

v7:
 - Further rebase

v8:
 - A few minor indentation and line length fixes

v9:
 - Yet another rebase since Maarten's patches reworked a bunch of the
   code (wm_pre, wm_post, etc.) that this was previously based on.

v10:
 - Move wm_mutex to dev_priv to protect against racing commits against
   disjoint CRTC sets. (Maarten)
 - Drop unnecessary clearing of cstate->wm.need_postvbl_update (Maarten)

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452108870-24204-1-git-send-email-matthew.d.roper@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
2016-01-07 11:56:49 +01:00
Jani Nikula
2dfb0b816d drm/i915: shut up gen8+ SDE irq dmesg noise, again
We still keep getting

[    4.249930] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!

This reverts

commit 820da7ae46
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Nov 25 16:47:23 2015 +0200

    Revert "drm/i915: shut up gen8+ SDE irq dmesg noise"

which in itself is a revert, so this is just doing

commit 97e5ed1111
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Oct 23 10:56:12 2015 +0200

    drm/i915: shut up gen8+ SDE irq dmesg noise

all over again. I'll stop pretending I understand what's going on like I
did when I thought I'd fixed this for good in

commit 6a39d7c986
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Nov 25 16:47:22 2015 +0200

    drm/i915: fix the SDE irq dmesg warnings properly

Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Reference: http://mid.gmane.org/20151213124945.GA5715@nuc-i3427.alporthouse.com
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92084
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 820da7ae46 ("Revert "drm/i915: shut up gen8+ SDE irq dmesg noise"")
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452155350-14658-1-git-send-email-jani.nikula@intel.com
2016-01-07 11:47:43 +02:00
Maarten Lankhorst
31d10b5701 drm/i915: Allow fuzzy matching in intel_compare_link_m_n
This prevents a unnecessary modeset on a dell XPS 13 (2016).

N is always a power of 2, which means that for fuzzy matching we should
compare for inequality on the n values, then do fuzzy matching on the m
values.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Tested-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/568D0E93.304@linux.intel.com
2016-01-06 14:20:30 +01:00
Matt Roper
d93c037246 drm/i915: Sanitize watermarks after hardware state readout (v4)
Although we can do a good job of reading out hardware state, the
graphics firmware may have programmed the watermarks in a creative way
that doesn't match how i915 would have chosen to program them.  We
shouldn't trust the firmware's watermark programming, but should rather
re-calculate how we think WM's should be programmed and then shove those
values into the hardware.

We can do this pretty easily by creating a dummy top-level state,
running it through the check process to calculate all the values, and
then just programming the watermarks for each CRTC.

v2:  Move watermark sanitization after our BIOS fb reconstruction; the
     watermark calculations that we do here need to look at pstate->fb,
     which isn't setup yet in intel_modeset_setup_hw_state(), even
     though we have an enabled & visible plane.

v3:
 - Don't move 'active = optimal' watermark assignment; we just undo
   that change in the next patch anyway.  (Ville)
 - Move atomic helper locking fix to separate patch.  (Maarten)

v4:
 - Grab connection_mutex before calling atomic helper to duplicate
   state.  The connector loop inside the helper will throw a WARN
   if we don't hold something to protect the connector list (and the
   helper itself doesn't try to lock the list).
 - Make failure to calculate watermarks for inherited state a WARN()
   since it probably indicates a serious problem in either our state
   readout code or our watermark code for this platform.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
2016-01-06 11:35:30 +01:00
Matt Roper
151268821e drm/i915: Add extra paranoia to ILK watermark calculations
Our low-level watermark calculation functions don't get called when the
CRTC is disabled or the relevant plane is invisible, so they should
never see a zero htotal or zero bpp.  However add some checks to ensure
this is true so that we don't wind up dividing by zero if we make a
mistake elsewhere in the driver (which the atomic watermark series has
revealed we might be).

References: http://lists.freedesktop.org/archives/intel-gfx/2015-October/077370.html
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449171462-30763-6-git-send-email-matthew.d.roper@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
2016-01-06 11:35:29 +01:00
Matt Roper
ee91a15972 drm/i915: Convert hsw_compute_linetime_wm to use in-flight state
When watermark calculation was moved up to the atomic check phase, the
code was updated to calculate based on in-flight atomic state rather
than already-committed state.  However the hsw_compute_linetime_wm()
didn't get updated and continued to pull values out of the
currently-committed CRTC state.  On platforms that call this function
(HSW/BDW only), this will cause problems when we go to enable the CRTC
since we'll pull the current mode (off) rather than the mode we're
calculating for and wind up with a divide by zero error.

This was an oversight in commit:

        commit a28170f338
        Author: Matt Roper <matthew.d.roper@intel.com>
        Date:   Thu Sep 24 15:53:16 2015 -0700

            drm/i915: Calculate ILK-style watermarks during atomic check (v3)

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449171462-30763-5-git-send-email-matthew.d.roper@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
2016-01-06 11:35:29 +01:00
Matt Roper
0a8d8a8667 drm/i915: Setup clipped src/dest coordinates during FB reconstruction (v2)
Plane state objects contain two copies of src/dest coordinates:  the
original (requested by userspace) coordinates in the base
drm_plane_state object, and a second, clipped copy (i.e., what we
actually want to program to the hardware) in intel_plane_state.  We've
only been setting up the former set of values during boot time FB
reconstruction, but we should really be initializing both.

Note that the code here probably still needs some more work since we
make a lot of assumptions about how the BIOS programmed the hardware
that may not always be true, especially on gen9+; e.g.,
 * Primary plane might not be positioned at 0,0
 * Primary plane could have been rotated by the BIOS
 * Primary plane might be scaled
 * The BIOS fb might be a single "extended mode" FB that spans
   multiple displays.
 * ...etc...

v2: Reword/expand commit message description of assumptions we make

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by(v1): Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449171462-30763-4-git-send-email-matthew.d.roper@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
2016-01-06 11:35:29 +01:00
Chris Wilson
42f1cae8c0 drm/i915: Restore inhibiting the load of the default context
Following a GPU reset, we may leave the context in a poorly defined
state, and reloading from that context will leave the GPU flummoxed. For
secondary contexts, this will lead to that context being banned - but
currently it is also causing the default context to become banned,
leading to turmoil in the shared state.

This is a regression from

commit 6702cf16e0 [v4.1]
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Mon Mar 16 16:00:58 2015 +0000

    drm/i915: Initialize all contexts

which quietly introduced the removal of the MI_RESTORE_INHIBIT on the
default context.

v2: Mark the global default context as uninitialized on GPU reset so
that the context-local workarounds are reloaded upon re-enabling.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1448630935-27377-1-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: stable@vger.kernel.org
[danvet: This seems to fix a gpu hand on after the first resume,
resulting in any future suspend operation failing with -EIO because
the gpu seems to be in a funky state. Somehow this patch fixes that.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-06 11:04:53 +01:00
Daniel Vetter
becd9ca2de drm/i915: Tune down rpm wakelock debug checks
They're causing massive amounts of dmesg noise and hence CI noise all
over the place. Enabling them for a bit was good enough to refresh our
task list of what's still needed to enable rpm by default.

To make sure we're not forgetting to make this noisy again add a FIXME
comment.

Fixes: da5827c366 ("drm/i915: add assert_rpm_wakelock_held helper")
Cc: Imre Deak <imre.deak@intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1452012847-4737-1-git-send-email-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2016-01-06 09:15:17 +01:00
Ankitprasad Sharma
c5236470fe drm/i915: Allow use of get_dma_address for stolen backed objects
i915_gem_object_get_dma_address function is used to retrieve the dma address
of a particular page so as to map it in a given GTT entry for CPU access.
This function would be used for stolen backed objects also for tasks like
pwrite,  clearing of the pages etc. So the obj->get_page.sg needs to be
initialized for the stolen objects also.

Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450765253-32104-2-git-send-email-ankitprasad.r.sharma@intel.com
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 17:46:27 +01:00
Dave Gordon
c5d46ee206 drm/i915: add kerneldoc for intel_lr_context_size()
This function was recently renamed & exposed, so now it gets documented

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1451996493-16079-1-git-send-email-david.s.gordon@intel.com
2016-01-05 16:14:33 +01:00
Jani Nikula
28c72840a7 drm/i915/dsi: be defensive about out of bounds operation byte
Untie the VBT based generic panel driver from the VBT parsing, so that
the two don't have to be updated in lockstep.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/01c71ac89a9db8bc7b8ae0fb05c50a5fae362dc4.1450702954.git.jani.nikula@intel.com
2016-01-05 16:38:28 +02:00
Jani Nikula
5cda0d20f9 drm/i915/dsi: be defensive about out of bounds sequence id
Untie the VBT based generic panel driver from the VBT parsing, so that
the two don't have to be updated in lockstep.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/7a6e3e7c4404c0e4dbcf003acd8737a6ecbe218f.1450702954.git.jani.nikula@intel.com
2016-01-05 16:38:11 +02:00
Jani Nikula
8d3ed2f313 drm/i915/bios: rewrite sequence block parsing
Make everything a bit more readable and clear.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/e8f2a62d78d90981a6b49fdf9ab3594f60a46033.1450702954.git.jani.nikula@intel.com
2016-01-05 16:38:01 +02:00
Jani Nikula
5db72099e8 drm/i915/bios: abstract finding the panel sequence block
Make the whole thing easier to read. While at it, make the parsing more
robust, and ensure we don't read past buffer being parsed.

v2: improve commit message (Daniel)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452001851-8967-1-git-send-email-jani.nikula@intel.com
2016-01-05 16:37:50 +02:00
Jani Nikula
08c0888b28 drm/i915/bios: have get_blocksize() support MIPI sequence block v3+
Have get_blocksize() support the special case of MIPI sequence block v3+
which has a separate field for size. Provide and use abstractions for
getting the blocksize given a pointer to the block "envelope",
i.e. pointer to the block id, and given a pointer to the block payload
data.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/e935bd5e119a83dd91214c47e6cd4f6ce8b2a17e.1450702954.git.jani.nikula@intel.com
2016-01-05 14:58:57 +02:00
Jani Nikula
0f8689f5bb drm/i915/bios: split the MIPI DSI VBT block parsing to two
There's two blocks to parse, have one function per block. The existing
one cuts neatly into two.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/6c9598e2b4d07e8d264617cdfe8b6527a74261f7.1450702954.git.jani.nikula@intel.com
2016-01-05 14:57:04 +02:00
Jani Nikula
513485fd10 drm/i915/bios: fix header define name for intel_bios.h
Just for OCD.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/730e41760133dbaa1e3ab1b91631ada18676810c.1450702954.git.jani.nikula@intel.com
2016-01-05 14:51:12 +02:00
Alex Dai
b6a5cd7ea2 drm/i915/guc: Add GuC ADS - enabling ADS
Set ADS enabling flag during GuC init.

Signed-off-by: Alex Dai <yu.dai@intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-6-git-send-email-yu.dai@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:34:49 +01:00
Alex Dai
5c148e044e drm/i915/guc: Add GuC ADS - MMIO reg state
GuC needs to know which registers and how they will be saved and
restored during event such as engine reset or power state changes.
For now only the base address of reg state is initialized. The
detail register table probably will be setup in future GuC TDR or
Preemption patch series.

Signed-off-by: Alex Dai <yu.dai@intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-5-git-send-email-yu.dai@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:34:41 +01:00
Alex Dai
463704d07f drm/i915/guc: Add GuC ADS - scheduler policies
GuC supports different scheduling policies for its four internal
queues. Currently these have been set to the same default values
as KMD_NORMAL queue.

Particularly POLICY_MAX_NUM_WI is set to 15 to match GuC internal
maximum submit queue numbers to avoid an out-of-space problem.
This value indicates max number of work items allowed to be queued
for one DPC process. A smaller value will let GuC schedule more
frequently while a larger number may increase chances to optimize
cmds (such as collapse cmds from same lrc) with risks that keeps
CS idle.

v1: tidy up code

Signed-off-by: Alex Dai <yu.dai@intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-4-git-send-email-yu.dai@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:33:40 +01:00
Alex Dai
68371a954c drm/i915/guc: Add GuC ADS (Addition Data Structure) - allocation
The GuC firmware uses this for various purposes. The ADS itself is
a chunk of memory created by driver to share with GuC. Its members
are usually addresses telling where GuC to access them, including
things like scheduler policies, register list that will be saved
and restored during reset etc.

This is the first patch of a series to enable GuC ADS. For now, we
only create the ADS obj whilst keep it disabled.

v1: remove dead code checking return of kmap_atomic (Chris Wilson)
v2: use kmap instead of the atomic version of it.

Signed-off-by: Alex Dai <yu.dai@intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-3-git-send-email-yu.dai@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:33:34 +01:00
Dave Gordon
95a66f7e71 drm/i915/guc: Expose (intel)_lr_context_size()
The GuC code needs to know the size of a logical context, so we
expose get_lr_context_size(), renaming it intel_lr_context__size()
to fit the naming conventions for nonstatic functions.

For: VIZ-2021
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: Alex Dai <yu.dai@intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450468812-4882-2-git-send-email-yu.dai@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:33:34 +01:00
Alex Dai
a7e02199ae drm/i915/guc: Move GuC wq_check_space to alloc_request_extras
Split GuC work queue space checking from submission and move it to
ring_alloc_request_extras. The reason is that failure in later
i915_add_request() won't be handled. In the case timeout happens,
driver can return early in order to handle the error.

v1: Move wq_reserve_space to ring_reserve_space
v2: Move wq_reserve_space to alloc_request_extras (Chris Wilson)
v3: The work queue head pointer is cached by driver now. So we can
    quickly return if space is available.
    s/reserve/check/g (Dave Gordon)
v4: Update cached wq head after ring doorbell; check wq space before
    ring doorbell in case unexpected error happens; call wq space
    check only when GuC submission is enabled. (Dave Gordon)

Signed-off-by: Alex Dai <yu.dai@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450295155-10050-1-git-send-email-yu.dai@intel.com
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:07:32 +01:00
Chris Wilson
c1a415e261 drm/i915: Disable shrinker for non-swapped backed objects
If the system has no available swap pages, we cannot make forward
progress in the shrinker by releasing active pages, only by releasing
purgeable pages which are immediately reaped. Take total_swap_pages into
account when counting up available objects to be shrunk and subsequently
shrinking them. By doing so, we avoid unbinding objects that cannot be
shrunk and so wasting CPU cycles flushing those objects from the GPU to
the system and then immediately back again (as they will more than
likely be reused shortly after).

Based on a patch by Akash Goel.

v2: frontswap registers extra swap pages available for the system, so it
is already include in the count of available swap pages.

v3: Use get_nr_swap_pages() to query the currently available amount of
swap space. This should also stop us from shrinking the GPU buffers if
we ever run out of swap space. Though at that point, we would expect the
oom-notifier to be running and failing miserably...

Reported-by: Akash Goel <akash.goel@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: linux-mm@kvack.org
Cc: Akash Goel <akash.goel@intel.com>
Cc: sourab.gupta@intel.com
Link: http://patchwork.freedesktop.org/patch/msgid/1449244734-25733-2-git-send-email-chris@chris-wilson.co.uk
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:05:38 +01:00
Michał Winiarski
934acce3c0 drm/i915: Avoid writing relocs with addresses in non-canonical form
According to PRM, some parts of HW require the addresses to be in
a canonical form, where bits [63:48] == [47]. Let's convert addresses to
canonical form prior to relocating and return converted offsets to
userspace. We also need to make sure that userspace is using addresses
in canonical form in case of softpin.

v2: Whitespace fixup, gen8_canonical_addr description (Chris, Ville)
v3: Rebase on top of softpin, fix a hole in relocate_entry,
    s/expect/require (Chris)
v4: Handle softpin in validate_exec_list (Chris)
v5: Convert back to canonical form at copy_to_user time (Chris)
v6: Don't use struct exec_object2 in place of exec_object
v7: Use sign_extend64 for converting to canonical form (Joonas),
    reject non-canonical and non-page-aligned offset for softpin (Chris)
v8: Convert back to non-canonical form in a function,
    split the test for EXEC_OBJECT_PINNED (Chris)
v9: s/canonial/canonical, drop accidental double newline (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451409892-13708-1-git-send-email-michal.winiarski@intel.com
Testcase: igt/gem_bad_reloc/negative-reloc-blt
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92699
Cc: drm-intel-fixes@lists.freedesktop.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-01-05 11:00:42 +01:00
Insu Yun
62ab420f74 i915: correctly handling failed allocation
Since devm_kzalloc can be failed, it needs to be checked
if not, NULL dereference could be happened.

Signed-off-by: Insu Yun <wuninsu@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451491169-35068-1-git-send-email-wuninsu@gmail.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-01-04 16:05:27 +02:00
Ben Widawsky
eba51190f3 drm/i915: Fix whitespace (trivial)
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1451427643-7266-1-git-send-email-benjamin.widawsky@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2015-12-30 11:19:50 +02:00
Gary Wang
f8d03ea005 drm/i915: increase the tries for HDMI hotplug live status checking
The total delay of HDMI hotplug detecting with 30ms is sometimes not
enoughtfor HDMI live status up with specific HDMI monitors in BSW platform.

After doing experiments for following monitors, it needs 80ms at least
for those worst cases.

Lenovo L246 1xwA (4 failed, necessary hot-plug delay: 58/40/60/40ms)
Philips HH2AP (9 failed, necessary hot-plug delay: 80/50/50/60/46/40/58/58/39ms)
BENQ ET-0035-N (6 failed, necessary hot-plug delay: 60/50/50/80/80/40ms)
DELL U2713HM (2 failed, necessary hot-plug delay: 58/59ms)
HP HP-LP2475w (5 failed, necessary hot-plug delay: 70/50/40/60/40ms)

It looks like 70-80 ms is BSW platform needs in some bad cases of the
monitors at this end (8 times delay at most). Keep less than 100ms for
HDCP pulse HPD low (with at least 100ms) to respond a plug out.

Reviewed-by: Cooper Chiou <cooper.chiou@intel.com>
Tested-by: Gary Wang <gary.c.wang@intel.com>
Cc: Gavin Hindman <gavin.hindman@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Gary Wang <gary.c.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450858295-12804-1-git-send-email-gary.c.wang@intel.com
Tested-by: Shobhit Kumar <shobhit.kumar@intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: 237ed86c69 ("drm/i915: Check live status before reading edid")
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-23 12:53:35 +01:00
Maarten Lankhorst
35c08f4346 drm/i915: Calculate visibility in check_plane correctly regardless of dpms.
When the crtc is configured but not active we currently clip to (0,0)x(0,0).
This results in differences in calculations depending on dpms setting.
When the crtc is enabled but not active run check_plane as if it were on,
but afterwards set plane_state->visible = false for the checks.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447945645-32005-13-git-send-email-maarten.lankhorst@linux.intel.com
2015-12-22 13:45:42 +01:00
Maarten Lankhorst
1a617b7765 drm/i915: Keep track of the cdclk as if all crtc's were active.
On skylake when calculating plane visibility with the crtc in
dpms off mode the real cdclk may be different from what it would be
if the crtc was active. This may result in a WARN_ON(cdclk < crtc_clock)
from skl_max_scale. The fix is to keep a atomic_cdclk that would be true
if all crtc's were active.

This is required to get the same calculations done correctly regardless
of dpms mode.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447945645-32005-12-git-send-email-maarten.lankhorst@linux.intel.com
2015-12-22 13:44:44 +01:00
Maarten Lankhorst
565602d750 drm/i915: Do not acquire crtc state to check clock during modeset, v4.
Parallel modesets are still not allowed, but this will allow updating
a different crtc during a modeset if the clock is not changed.

Additionally when all pipes are DPMS off the cdclk will be lowered
to the minimum allowed.

Changes since v1:
- Add dev_priv->active_crtcs for tracking which crtcs are active.
- Rename min_cdclk to min_pixclk and move to dev_priv.
- Add a active_crtcs mask which is updated atomically.
- Add intel_atomic_state->modeset which is set on modesets.
- Commit new pixclk/active_crtcs right after state swap.
Changes since v2:
- Make the changes related to max_pixel_rate calculations more readable.
Changes since v3:
- Add cherryview and missing WARN_ON to readout.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
2015-12-22 13:42:27 +01:00
Maarten Lankhorst
bf8a0af0cc drm/i915/skl: Do not allow scaling when crtc is disabled.
This fixes a warning when the crtc is turned off. In that case fb
will be NULL, and crtc_clock will be 0. Because the crtc is no longer
active this is not a bug, and shouldn't trigger the WARN_ON.

Also remove handling a null crtc_state, with all transitional helpers
gone this can no longer happen.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448360945-5723-2-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
2015-12-22 13:42:27 +01:00
Jani Nikula
dd97950a4c drm/i915/bios: add proper documentation for the Video BIOS Table (VBT)
Add an overview and documentation for the VBT/BDB header structures.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/3d826d4600688ca3518713776ab5bd8a8fc9f20f.1450702954.git.jani.nikula@intel.com
2015-12-22 14:37:07 +02:00
Ville Syrjälä
0bff485865 drm/i915: Unbreak check_digital_port_conflicts()
Atomic changes broke check_digital_port_conflicts(). It needs to look
at the global situation instead of just trying to find a conflict
within the current atomic state.

This bug made my HSW explode spectacularly after I had split the DDI
encoders into separate DP and HDMI encoders. With the fix, things
seem much more solid.

I hope holding the connection_mutex is enough protection that we can
actually walk the connectors even if they're not part of the current
atomic state...

v2: Regenerate the patch so that it actually applies (Jani)

Cc: stable@vger.kernel.org
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Fixes: 5448a00d3f ("drm/i915: Don't use staged config in check_digital_port_conflicts()")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449764551-12466-1-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2015-12-22 14:28:16 +02:00
Joonas Lahtinen
152b22627c drm/i915: Compile-time concatenate WARN_ON macro strings
Using __stringify(x) instead of #x adds support for macros as
a parameter and compile-time concatenation reduces the runtime
overhead.

Slightly increases the .text size but should not matter.

v2:
- Define I915_STATE_WARN_ON though I915_STATE_WARN
  (Bikeshed inspiration by Chris)

v3:
- More specific commit message

v4:
- Do not directly pass arbitary string as format, instead
  guard with "%s" (Dave)

Cc: Rob Clark <robdclark@gmail.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450441647-23924-3-git-send-email-joonas.lahtinen@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-22 10:03:06 +01:00
Joonas Lahtinen
32753cb863 drm/i915: Simplify _STATE_ debug macros
Take advantage of WARN return value to simplify the flow.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450441647-23924-2-git-send-email-joonas.lahtinen@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-22 10:02:57 +01:00
Lukas Wunner
4601b933c9 drm/i915: Remove obsolete code from intelfb_alloc()
Clean up after 0c82312f3f ("drm/i915: Pin the ifbdev for the
info->system_base GGTT mmapping"):

At each of the remaining "goto out" in intelfb_alloc(), fb can only be
either an ERR_PTR or NULL, so the call to drm_framebuffer_unreference()
is now obsolete.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: http://patchwork.freedesktop.org/patch/msgid/56756c41.c306c20a.d0602.1830SMTPIN_ADDED_MISSING@mx.google.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 17:03:25 +01:00
Ville Syrjälä
b29ec92c4f drm/i915: Workaround CHV pipe C cursor fail
Turns out CHV pipe C was glued on somewhat poorly, and there's something
wrong with the cursor. If the cursor straddles the left screen edge,
and is then moved away from the edge or disabled, the pipe will often
underrun. If enough underruns are triggered quickly enough the pipe
will fall over and die (it just scans out a solid color and reports
a constant underrun). We need to turn the disp2d power well off and
on again to recover the pipe.

None of that is very nice for the user, so let's just refuse to place
the cursor in the compromised position. The ddx appears to fall back
to swcursor when the ioctl returns an error, so theoretically there's
no loss of functionality for the user (discounting swcursor bugs).
I suppose most cursors images actually have the hotspot not exactly
at 0,0 so under typical conditions the fallback will in fact kick in
as soon as the cursor touches the left edge of the screen.

Any atomic compositor should anyway be prepared to fall back to
GPU composition when things don't work out, so there should be no
problem with those.

Other things that I tried to solve this include flipping all
display related clock gating knobs I could find, increasing the
minimum gtt alignment all the way up to 512k. I also tried to see
if there are more specific screen coordinates that hit the bug, but
the findings were somewhat inconclusive. Sometimes the failures
happen almost across the whole left edge, sometimes more at the very
top and around the bottom half. I wasn't able to find any real pattern
to these variations, so it seems our only choice is to just refuse
to straddle the left screen edge at all.

Cc: stable@vger.kernel.org
Cc: Jason Plum <max@warheads.net>
Testcase: igt/kms_chv_cursor_fail
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92826
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450459479-16286-1-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 14:50:53 +01:00
Joonas Lahtinen
482bfe5cc7 drm/i915: Reorder i915_params struct.
Move all the bool variables to the end as per the comment.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450436898-20408-3-git-send-email-joonas.lahtinen@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 14:35:12 +01:00
Joonas Lahtinen
c838d719d6 drm/i915: Decouple struct i915_params i915 into i915_params.h
Otherwise usage in the i915 debug macros yields problems due to
i915_drv.h <-> i915_trace.h <-> intel_drv.h include loops.

v2:
- Document not-so-obvious need for linux/cache.h (Chris)

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450436898-20408-2-git-send-email-joonas.lahtinen@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 14:35:03 +01:00
Ben Widawsky
1a5a9ce70f drm/i915: Limit VF cache invalidate workaround usage to gen9
It is unclear if this is even required on BXT.

v2: Make sure to set the default value to false. Uncertain how my compiler
doesn't complain with v1.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450374597-7021-1-git-send-email-benjamin.widawsky@intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 13:05:36 +01:00
Gary Wang
61fb3980dd drm/i915: Correct max delay for HDMI hotplug live status checking
The total delay of HDMI hotplug detecting with 30ms have already
been split into a resolution of 3 retries of 10ms each, for the worst
cases. But it still suffered from only waiting 10ms at most in
intel_hdmi_detect(). This patch corrects it by reading hotplug status
with 4 times at most for 30ms delay.

v2:
- straight up to loop execution for more clear in code readability
- mdelay will replace with msleep by Daniel's new patch

	drm/i915: mdelay(10) considered harmful

- suggest to re-evaluate try times for being compatible to old HDMI monitor

Reviewed-by: Cooper Chiou <cooper.chiou@intel.com>
Tested-by: Gary Wang <gary.c.wang@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Gavin Hindman <gavin.hindman@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Gary Wang <gary.c.wang@intel.com>
[danvet: fixup conflict with s/mdelay/msleep/ patch.]
Cc: drm-intel-fixes@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 11:28:33 +01:00
Chris Wilson
c140330b5e drm/i915: Move Braswell stop_machine GGTT insertion workaround
There was a silent conflict between

commit 0a87871626
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Oct 15 14:23:01 2015 +0200

    drm/i915: restore ggtt double-bind avoidance

and

commit 5bab6f60cb
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Oct 23 18:43:32 2015 +0100

    drm/i915: Serialise updates to GGTT with access through GGTT on Braswell

thankfully caught by the extra WARN safegaurd in 0a878716. Since we now
override the GGTT insert_pages callback when installing the aliasing
ppgtt, we assert that the callback is the original ggtt routine.
However, on Braswell we now use a different insertion routine to
serialise access through the GGTT with updating the PTE and hence the
conflict. To avoid the conflict, move the custom insertion routine for
Braswell down a level.

Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447859979-20107-1-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-21 11:17:56 +01:00
Mika Kuoppala
06e668ac91 drm/i915: Apply broader WaRsDisableCoarsePowerGating for guc also
commit 344df9809f ("drm/i915/skl: Disable coarse power gating up until F0")
failed to take into account that the same workaround is used in guc
when forcewake is sampled.

Wrap the condition check inside a macro and use it in both places
to fix the guc side scope.

Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450286318-6854-1-git-send-email-mika.kuoppala@intel.com
2015-12-18 21:57:07 +02:00
Daniel Vetter
7447a2b221 drm/i915: Update DRIVER_DATE to 20151218
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-18 20:26:17 +01:00
Mika Kuoppala
e238659ddd drm/i915/skl: Default to noncoherent access up to F0
The workarounds for disabling hdc invalidation and also forcing
context to be non coherent, are advised to be used up until rev D0.

However as it was found that rev F0, without the
WaForceEnableNonCoherent might system hang if the mesa
tried to use coherent mode.

As these two workarounds are about non coherent access, are
grouped in scope and they point the same HSD, increase the
scope of both to set default behaviour to non coherent access.

References: HSD: gen9lp/2131413
References: http://lists.freedesktop.org/archives/mesa-dev/2015-November/101515.html
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Cc: Francisco Jerez <currojerez@riseup.net>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450448093-22906-1-git-send-email-mika.kuoppala@intel.com
2015-12-18 19:55:03 +02:00
Chris Wilson
821485dc2a drm/i915: Only spin whilst waiting on the current request
Limit busywaiting only to the request currently being processed by the
GPU. If the request is not currently being processed by the GPU, there
is a very low likelihood of it being completed within the 2 microsecond
spin timeout and so we will just be wasting CPU cycles.

v2: Check for logical inversion when rebasing - we were incorrectly
checking for this request being active, and instead busywaiting for
when the GPU was not yet processing the request of interest.

v3: Try another colour for the seqno names.
v4: Another colour for the function names.

v5: Remove the forced coherency when checking for the active request. On
reflection and plenty of recent experimentation, the issue is not a
cache coherency problem - but an irq/seqno ordering problem (timing issue).
Here, we do not need the w/a to force ordering of the read with an
interrupt.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: "Rogozhkin, Dmitry V" <dmitry.v.rogozhkin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Eero Tamminen <eero.t.tamminen@intel.com>
Cc: "Rantala, Valtteri" <valtteri.rantala@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449833608-22125-4-git-send-email-chris@chris-wilson.co.uk
2015-12-18 17:11:56 +01:00
Chris Wilson
ca5b721e23 drm/i915: Limit the busy wait on requests to 5us not 10ms!
When waiting for high frequency requests, the finite amount of time
required to set up the irq and wait upon it limits the response rate. By
busywaiting on the request completion for a short while we can service
the high frequency waits as quick as possible. However, if it is a slow
request, we want to sleep as quickly as possible. The tradeoff between
waiting and sleeping is roughly the time it takes to sleep on a request,
on the order of a microsecond. Based on measurements of synchronous
workloads from across big core and little atom, I have set the limit for
busywaiting as 10 microseconds. In most of the synchronous cases, we can
reduce the limit down to as little as 2 miscroseconds, but that leaves
quite a few test cases regressing by factors of 3 and more.

The code currently uses the jiffie clock, but that is far too coarse (on
the order of 10 milliseconds) and results in poor interactivity as the
CPU ends up being hogged by slow requests. To get microsecond resolution
we need to use a high resolution timer. The cheapest of which is polling
local_clock(), but that is only valid on the same CPU. If we switch CPUs
because the task was preempted, we can also use that as an indicator that
 the system is too busy to waste cycles on spinning and we should sleep
instead.

__i915_spin_request was introduced in
commit 2def4ad99b [v4.2]
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Apr 7 16:20:41 2015 +0100

     drm/i915: Optimistically spin for the request completion

v2: Drop full u64 for unsigned long - the timer is 32bit wraparound safe,
so we can use native register sizes on smaller architectures. Mention
the approximate microseconds units for elapsed time and add some extra
comments describing the reason for busywaiting.

v3: Raise the limit to 10us
v4: Now 5us.

Reported-by: Jens Axboe <axboe@kernel.dk>
Link: https://lkml.org/lkml/2015/11/12/621
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: "Rogozhkin, Dmitry V" <dmitry.v.rogozhkin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Eero Tamminen <eero.t.tamminen@intel.com>
Cc: "Rantala, Valtteri" <valtteri.rantala@intel.com>
Cc: stable@vger.kernel.org

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449833608-22125-3-git-send-email-chris@chris-wilson.co.uk
2015-12-18 17:11:52 +01:00