Op 19-09-17 om 12:24 schreef Ville Syrjälä:
> On Tue, Sep 19, 2017 at 11:06:52AM +0200, Maarten Lankhorst wrote:
>> Op 18-09-17 om 17:03 schreef Ville Syrjälä:
>>> On Mon, Sep 18, 2017 at 12:12:50PM +0200, Maarten Lankhorst wrote:
>>>> Commit b44d5c0c105a ("drm/i915: Always wait for flip_done, v2.") removed
>>>> the call to wait_for_vblanks and replaced it with flip_done.
>>>>
>>>> Unfortunately legacy_cursor_update was unset too late, and the
>>>> replacement call drm_atomic_helper_wait_for_flip_done() was
>>>> a noop. Make sure that its unset before setup_commit() is
>>>> called to fix this issue.
>>>>
>>>> Changes since v1:
>>>> - Force vblank wait for watermarks not yet converted to atomic too. (Ville)
>>>> - Use for_each_new_intel_crtc_in_state. (Ville)
>>>>
>>>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
>>>> Fixes: b44d5c0c105a ("drm/i915: Always wait for flip_done, v2.")
>>>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102675
>>>> Testcase: kms_cursor_crc
>>>> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
>>>> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
>>>> Reported-by: Marta Löfstedt <marta.lofstedt@xxxxxxxxx>
>>>> Cc: Marta Löfstedt <marta.lofstedt@xxxxxxxxx>
>>>> Tested-by: Marta Löfstedt <marta.lofstedt@xxxxxxxxx>
>>>> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>>>> ---
>>>> drivers/gpu/drm/i915/intel_display.c | 45 +++++++++++++++++++++---------------
>>>> 1 file changed, 26 insertions(+), 19 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>>>> index 8599e425abb1..8d051256da1e 100644
>>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>>> @@ -12517,21 +12517,10 @@ static int intel_atomic_commit(struct drm_device *dev,
>>>> struct drm_i915_private *dev_priv = to_i915(dev);
>>>> int ret = 0;
>>>>
>>>> - ret = drm_atomic_helper_setup_commit(state, nonblock);
>>>> - if (ret)
>>>> - return ret;
>>>> -
>>>> drm_atomic_state_get(state);
>>>> i915_sw_fence_init(&intel_state->commit_ready,
>>>> intel_atomic_commit_ready);
>>>>
>>>> - ret = intel_atomic_prepare_commit(dev, state);
>>>> - if (ret) {
>>>> - DRM_DEBUG_ATOMIC("Preparing state failed with %i\n", ret);
>>>> - i915_sw_fence_commit(&intel_state->commit_ready);
>>>> - return ret;
>>>> - }
>>>> -
>>>> /*
>>>> * The intel_legacy_cursor_update() fast path takes care
>>>> * of avoiding the vblank waits for simple cursor
>>>> @@ -12540,19 +12529,37 @@ static int intel_atomic_commit(struct drm_device *dev,
>>>> * updates happen during the correct frames. Gen9+ have
>>>> * double buffered watermarks and so shouldn't need this.
>>>> *
>>>> - * Do this after drm_atomic_helper_setup_commit() and
>>>> - * intel_atomic_prepare_commit() because we still want
>>>> - * to skip the flip and fb cleanup waits. Although that
>>>> - * does risk yanking the mapping from under the display
>>>> - * engine.
>>>> + * Unset state->legacy_cursor_update before the call to
>>>> + * drm_atomic_helper_setup_commit() because otherwise
>>>> + * drm_atomic_helper_wait_for_flip_done() is a noop and
>>>> + * we get FIFO underruns because we didn't wait
>>>> + * for vblank.
>>>> *
>>>> * FIXME doing watermarks and fb cleanup from a vblank worker
>>>> * (assuming we had any) would solve these problems.
>>>> */
>>>> - if (INTEL_GEN(dev_priv) < 9)
>>>> - state->legacy_cursor_update = false;
>>>> + if (INTEL_GEN(dev_priv) < 9 && state->legacy_cursor_update) {
>>>> + struct intel_crtc_state *new_crtc_state;
>>>> + struct intel_crtc *crtc;
>>>> + int i;
>>>> +
>>>> + for_each_new_intel_crtc_in_state(intel_state, crtc, new_crtc_state, i)
>>>> + if (new_crtc_state->wm.need_postvbl_update ||
>>>> + new_crtc_state->update_wm_post)
>>>> + state->legacy_cursor_update = false;
>>> Hmm. I guess that's better. But I still don't see why you want to change
>>> this bit of code in this patch. AFAICS it's got nothing to do with the fix
>>> itself, and instead it's just trying to optimize some cursor updates
>>> that were kicked over to the slow path. Or am I missing something?
>> We accidentally removed the vblank wait for the slowpath, but I don't think we should reintroduce the vblank except where we need it..
> IMO any regression fix should ideally get us back exactly where we were.
>
Ok I'll send it out as separate patch then..
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