Ville Syrjälä reported that in the majority of wait_for(I915_READ()) he
inspect, most completed within the first couple of reads and that the
delay between those wait_for() reads was the ratelimiting step for many
code paths. For example, __gen6_update_ring_freq() was blamed for
slowing down boot by many milliseconds, but under Ville's scrutiny the
issue was just excessive delay waiting for sandybridge_pcode_write().
We can eliminate the wait by initially using a busyspin upon the register
read and only fallback to the sleeping loop in cases where the hardware
is indeed too slow. A threshold of 2 microseconds is used as the initial
ballpark.
To avoid excessive code bloating from converting every wait_for() into a
hybrid busy/sleep loop, we extend wait_for_register_fw() and export it
for use by other callers.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467297225-21379-1-git-send-email-chris@chris-wilson.co.uk
Since commit 2ed53a94d8 ("drm/i915: On GPU reset, set the HWS
breadcrumb to the last seqno") once a hang is completed, the seqno is
advanced past all current requests. With this we know that if we wake up
from waiting for a request, if a hang has occurred and reset completed,
our request will be considered complete (i.e.
i915_gem_request_completed() returns true). Therefore we only need to
worry about the situation where a hang has occurred, but not yet reset,
where we may need to release our struct_mutex. Since we don't need to
detect the completed reset using the global gpu_error->reset_counter
anymore, we do not need to track the reset_counter epoch inside the
request.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467211874-11552-1-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Arun Siluvery <arun.siluvery@linux.intel.com>
When a display update triggers a DDB re-allocation, we should start by
assuming that only the updated pipes need to be re-allocated (we have
logic later that may add additional pipes if, e.g., a modeset triggers a
change to the global allocation).
We were erroneously using the _active_ pipes as our starting point
rather than the changed pipes. This causes us to grab CRTC locks that
we didn't actually need, reducing parallelism. Given the recent
non-blocking atomic changes, it also causes legacy pageflips against one
CRTC to return -EBUSY if there's an outstanding pageflip against a
different CRTC (a situation easily triggered via compositors like
Weston).
Fixes: 98d39494d3 ("drm/i915/gen9: Compute DDB allocation at atomic check time (v4)")
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/1467070964-14864-1-git-send-email-matthew.d.roper@intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
If a context waiting for VBlank were switched out, switching
in the next context and generating a CSB event in the process,
then the GuC would have to put the context back in the queue,
and then observe the subsequent VBlank interrupt so that it
could resubmit the suspended context.
However, we always set the CTX_CTRL_INHIBIT_SYN_CTX_SWITCH bit
in the RING_CONTEXT_CONTROL register, so this case cannot occur.
Furthermore we don't use the GuC's internal scheduler or allow
it to auto-resubmit workloads. Consequently, the GuC doesn't
need to see VBlanks, and by sending them to it we may be waking
it up unnecessarily, which might reduce RC6 residency and
increase power consumption.
So this patch removes the setting of the GFC_FORWARD_VBLANK
field from the code that diverts interrupts towards the GuC.
(The code to direct interrupts to the host, OTOH, continues to
explicitly set the field to "never send VBlanks to the GuC".)
v3:
Remove the line of code completely (original set the field
to ALWAYS forward, v1 changed it to CONDITIONAL forwarding,
v2 explicitly set it to NEVER, v3 just doesn't touch it at
all, as we know it's already set to NEVER).
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (previous version)
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466780277-23435-1-git-send-email-david.s.gordon@intel.com
Gen8 versions of these macros were updated a few months ago
(e8ebd8e drm/i915: eliminate 'temp' in gen8_for_each macros)
originally because at least one iterator could generate an
out of bounds access, but also because eliminating the 'temp'
parameter generated smaller and faster code.
Matthew Auld recently noticed the same problem with the gen6
versions and provided a patch
https://lists.freedesktop.org/archives/intel-gfx/2016-June/099334.html
but while we're changing these, we might as well make them as
much like the gen8 versions as possible, including the style
of using "&& (..., true)" rather than ": (..., 1) : 0", and
of course eliminating the redundant 'temp'.
Furthermore, the "all_pdes" version is only used in one place,
so we can improve code efficiency by changing both the macro
parameters and the calling code to reduce extra dereferences.
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466793466-23500-1-git-send-email-david.s.gordon@intel.com
This is so that we have symmetry with intel_lrc.c and avoid a source of
if (i915.enable_execlists) layering violation within i915_gem_context.c -
that is we move the specific handling of the dev_priv->kernel_context
for legacy submission into the legacy submission code.
This depends upon the init/fini ordering between contexts and engines
already defined by intel_lrc.c, and also exporting the context alignment
required for pinning the legacy context.
v2: Separate out pin/unpin context funcs for greater symmetry with
intel_lrc. One more step towards unifying behaviour between the two
classes of engines and towards fixing another bug in i915_switch_context
vs requests.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466776558-21516-2-git-send-email-chris@chris-wilson.co.uk
To complete the transition to manual control of load/unload, we need to
take over unloading from i915_pci_remove(). This allows us to correctly
order our unregister vs shutdown phases, which currently are inverted
due to the midlayer.
However, the unload sequence is still invalid as we shutdown the driver
with the last reference. Ideally, all we want to do is remove the
userspace access on device removal, deferring the cleanup to the
drm_dev_release() - breaking the reference cycles is then left as an
exercise for the reader.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-7-git-send-email-chris@chris-wilson.co.uk
Take control over allocating, loading and registering the driver from the
DRM midlayer by performing it manually from i915_pci_probe. This allows
us to carefully control the order of when we setup the hardware vs when
it becomes visible to third parties (including userspace). The current
ordering makes the driver visible to userspace first (in order to
coordinate with removed DRI1 userspace), but that ordering incurs risk.
The risk increases as we strive for more asynchronous loading.
One side effect of controlling the allocation is that we can allocate
both the drm_device + drm_i915_private in one block, the next step
towards subclassing.
Unload is still left as before, a mix of midlayer and driver.
v2: After drm_dev_init(), we should call drm_dev_unref() so that we call
drm_dev_release() and free everything from drm_dev_init().
v3: Fixup missed error code for failing to allocate dev_priv
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-6-git-send-email-chris@chris-wilson.co.uk
Currently debugfs files are created before the driver is even loads.
This gives the opportunity for userspace to open that interface and poke
around before the backing data structures are initialised - with the
possibility of oopsing or worse.
Move the creation of the debugfs files to our registration phase, where
we announce our presence to the world when we are ready, i.e the
sequence changes from
drm_dev_register()
-> drm_minor_register()
-> drm_debugfs_init()
-> i915_debugfs_init()
-> i915_driver_load()
to
drm_dev_register()
-> drm_minor_register()
-> drm_debugfs_init()
-> i915_driver_load()
-> i915_debugfs_register()
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-5-git-send-email-chris@chris-wilson.co.uk
Effectively removes one layer of indirection between the mask of
possible engines and the engine constructors. Instead of spelling
out in code the mapping of HAS_<engine> to constructors, makes
more use of the recently added data driven approach by putting
engine constructor vfuncs into the table as well.
Effect is fewer lines of source and smaller binary.
At the same time simplify the error handling since engine
destructors can run on unitialized engines anyway.
Similar approach could be done for legacy submission is wanted.
v2: Removed ugly BUILD_BUG_ONs in favour of newly introduced
ENGINE_MASK and HAS_ENGINE macros.
Also removed the forward declarations by shuffling functions
around.
v3: Warn when logical_rings table does not contain enough data
and disable the engines which could not be initialized.
(Chris Wilson)
v4: Chris Wilson suggested a nicer engine init loop.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466689961-23232-1-git-send-email-tvrtko.ursulin@linux.intel.com
Backmerge drm-next for the reworked device register/unregistering.
Chris Wilson needs that to be able to land his i915 load/unload
demidlayering.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
MT8173 HDMI support
- device tree binding documentation for MT8173 HDMI encoder, CEC, DDC,
and PHY
- drivers for MT8173 HDMI encoder, CEC (HPD only for now), DDC, and PHY
- enable HDMI output via a custom SMCCC call
- add ddc-i2c-bus property to HDMI connector device tree binding
* tag 'mediatek-drm-2016-06-20' of git://git.pengutronix.de/git/pza/linux:
dt-bindings: hdmi-connector: add DDC I2C bus phandle documentation
drm/mediatek: enable hdmi output control bit
drm/mediatek: Add HDMI support
dt-bindings: drm/mediatek: Add Mediatek HDMI dts binding
some rcar-du fixes.
* 'drm/next/du' of git://linuxtv.org/pinchartl/media:
drm: rcar-du: error message is not needed for EPROBE_DEFER
drm: rcar-du: error message is not needed for drm_vblank_init()
rcar-du: add/rename DEFR6 TCON bits
