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author | Chris Wilson <chris@chris-wilson.co.uk> | 2017-09-11 09:41:26 +0100 |
---|---|---|
committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-09-19 13:06:21 +0100 |
commit | 81c0ed21aa91230ab6c0de945155aa5c0626d001 (patch) | |
tree | 29e6b323814e56a77bec1c09845f68a678fdfc54 /drivers/gpu/drm/i915/Kconfig | |
parent | f46f156ea7704a40577800c3df63b599121a87ec (diff) |
drm/i915/fence: Avoid del_timer_sync() from inside a timer
A fence may be signaled from any context, including from inside a timer.
One example is timer_i915_sw_fence_wake() which is used to provide a
safety-net when waiting on an external fence. If the external fence is
not signaled within a timely fashion, we signal our fence on its behalf,
and so we then may process subsequent fences in the chain from within
that timer context.
Given that dma_i915_sw_fence_wake() may be from inside a timer, we cannot
then use del_timer_sync() as that requires the timer lock for itself. To
circumvent this, while trying to keep the signal propagation as low
latency as possible, move the completion into a worker and use a bit of
atomic switheroo to serialise the timer-callback and the dma-callback.
Testcase: igt/gem_eio/in-flight-external
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170911084135.22903-3-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/Kconfig')
-rw-r--r-- | drivers/gpu/drm/i915/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig index e9e64e8e9765..dfd95889f4b7 100644 --- a/drivers/gpu/drm/i915/Kconfig +++ b/drivers/gpu/drm/i915/Kconfig @@ -12,6 +12,7 @@ config DRM_I915 select DRM_PANEL select DRM_MIPI_DSI select RELAY + select IRQ_WORK # i915 depends on ACPI_VIDEO when ACPI is enabled # but for select to work, need to select ACPI_VIDEO's dependencies, ick select BACKLIGHT_LCD_SUPPORT if ACPI |