[PATCH hwc] drm_hwcomposer: Support assigning planes in ValidateDisplay

Stefan Schake stschake at gmail.com
Thu May 17 23:25:57 UTC 2018


Hey Rob,

On Fri, May 18, 2018 at 12:08 AM, Rob Herring <robh at kernel.org> wrote:
> In order to assign planes to layers in ValidateDisplay, testing
> compositing with a DRM atomic modeset test is needed as PresentDisplay
> is too late. This means most of PresentDisplay needs to be run from
> ValidateDisplay, so refactor PresentDisplay and plumb a test flag down
> the stack.
>
> Signed-off-by: Rob Herring <robh at kernel.org>
> ---
> Based on my GL comp removal work. Adding atomic test path turned out to
> be easier than using the Planner directly.
>
>  drmdisplaycompositor.cpp |  4 +-
>  drmdisplaycompositor.h   |  2 +-
>  drmhwctwo.cpp            | 79 ++++++++++++++++++++++++++++++++++------
>  drmhwctwo.h              |  1 +
>  4 files changed, 73 insertions(+), 13 deletions(-)
>
> diff --git a/drmdisplaycompositor.cpp b/drmdisplaycompositor.cpp
> index 2f9f6c6772da..ceee6b1a4bd6 100644
> --- a/drmdisplaycompositor.cpp
> +++ b/drmdisplaycompositor.cpp
> @@ -469,7 +469,7 @@ void DrmDisplayCompositor::ApplyFrame(
>  }
>
>  int DrmDisplayCompositor::ApplyComposition(
> -    std::unique_ptr<DrmDisplayComposition> composition) {
> +    std::unique_ptr<DrmDisplayComposition> composition, bool test) {

Since ApplyComposition just calls CommitFrame which already has test
support, can we reuse that for a TestComposition function?

>    int ret = 0;
>    switch (composition->type()) {
>      case DRM_COMPOSITION_TYPE_FRAME:
> @@ -481,6 +481,8 @@ int DrmDisplayCompositor::ApplyComposition(
>            ALOGE("Commit test failed for display %d, FIXME", display_);
>            return ret;
>          }
> +        if (test)
> +          return 0;

Then we could also drop this hunk.

>        }
>
>        ApplyFrame(std::move(composition), ret);
> diff --git a/drmdisplaycompositor.h b/drmdisplaycompositor.h
> index ed46873c3409..7c5ebb005dc4 100644
> --- a/drmdisplaycompositor.h
> +++ b/drmdisplaycompositor.h
> @@ -43,7 +43,7 @@ class DrmDisplayCompositor {
>    int Init(DrmResources *drm, int display);
>
>    std::unique_ptr<DrmDisplayComposition> CreateComposition() const;
> -  int ApplyComposition(std::unique_ptr<DrmDisplayComposition> composition);
> +  int ApplyComposition(std::unique_ptr<DrmDisplayComposition> composition, bool test);

And this one.

>    int Composite();
>    void Dump(std::ostringstream *out) const;
>
> diff --git a/drmhwctwo.cpp b/drmhwctwo.cpp
> index deaf14363e8c..19f73e721154 100644
> --- a/drmhwctwo.cpp
> +++ b/drmhwctwo.cpp
> @@ -480,8 +480,7 @@ void DrmHwcTwo::HwcDisplay::AddFenceToRetireFence(int fd) {
>    }
>  }
>
> -HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
> -  supported(__func__);
> +HWC2::Error DrmHwcTwo::HwcDisplay::CreateComposition(bool test) {

This is called CreateComposition, but it also tests and even commits.
If this only sets up the DrmDisplayComposition, we could just have the
test and commit in Validate/Present respectively and drop the flag.
Unfortunately it also uses and mutates the layer state, and moving that
into Present/Validate from here looks more difficult.

>    std::vector<DrmCompositionDisplayLayersMap> layers_map;
>    layers_map.emplace_back();
>    DrmCompositionDisplayLayersMap &map = layers_map.back();
> @@ -494,7 +493,13 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
>    uint32_t client_z_order = 0;
>    std::map<uint32_t, DrmHwcTwo::HwcLayer *> z_map;
>    for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
> -    switch (l.second.validated_type()) {
> +    HWC2::Composition comp_type;
> +    if (test)
> +      comp_type = l.second.sf_type();
> +    else
> +      comp_type = l.second.validated_type();
> +
> +    switch (comp_type) {
>        case HWC2::Composition::Device:
>          z_map.emplace(std::make_pair(l.second.z_order(), &l.second));
>          break;
> @@ -510,6 +515,10 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
>    if (use_client_layer)
>      z_map.emplace(std::make_pair(client_z_order, &client_layer_));
>
> +  if (z_map.empty())
> +    return HWC2::Error::BadLayer;
> +
> +

Extra newline.

>    // now that they're ordered by z, add them to the composition
>    for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
>      DrmHwcLayer layer;
> @@ -521,10 +530,6 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
>      }
>      map.layers.emplace_back(std::move(layer));
>    }
> -  if (map.layers.empty()) {
> -    *retire_fence = -1;
> -    return HWC2::Error::None;
> -  }
>
>    std::unique_ptr<DrmDisplayComposition> composition =
>        compositor_.CreateComposition();
> @@ -555,13 +560,29 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
>      i = overlay_planes.erase(i);
>    }
>
> -  AddFenceToRetireFence(composition->take_out_fence());
> +  if (!test)
> +    AddFenceToRetireFence(composition->take_out_fence());
>
> -  ret = compositor_.ApplyComposition(std::move(composition));
> +  ret = compositor_.ApplyComposition(std::move(composition), test);
>    if (ret) {
>      ALOGE("Failed to apply the frame composition ret=%d", ret);
>      return HWC2::Error::BadParameter;
>    }
> +  return HWC2::Error::None;
> +}
> +
> +HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
> +  supported(__func__);
> +  HWC2::Error ret;
> +
> +  ret = CreateComposition(false);
> +  if (ret == HWC2::Error::BadLayer) {
> +      // Can we really have no client or device layers?
> +      *retire_fence = -1;
> +      return HWC2::Error::None;
> +  }
> +  if (ret != HWC2::Error::None)
> +    return ret;
>
>    // The retire fence returned here is for the last frame, so return it and
>    // promote the next retire fence
> @@ -586,7 +607,7 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetActiveConfig(hwc2_config_t config) {
>        compositor_.CreateComposition();
>    composition->Init(drm_, crtc_, importer_.get(), planner_.get(), frame_no_);
>    int ret = composition->SetDisplayMode(*mode);
> -  ret = compositor_.ApplyComposition(std::move(composition));
> +  ret = compositor_.ApplyComposition(std::move(composition), false);
>    if (ret) {
>      ALOGE("Failed to queue dpms composition on %d", ret);
>      return HWC2::Error::BadConfig;
> @@ -666,7 +687,7 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetPowerMode(int32_t mode_in) {
>        compositor_.CreateComposition();
>    composition->Init(drm_, crtc_, importer_.get(), planner_.get(), frame_no_);
>    composition->SetDpmsMode(dpms_value);
> -  int ret = compositor_.ApplyComposition(std::move(composition));
> +  int ret = compositor_.ApplyComposition(std::move(composition), false);

With a TestComposition we can drop the two hunks here.

>    if (ret) {
>      ALOGE("Failed to apply the dpms composition ret=%d", ret);
>      return HWC2::Error::BadParameter;
> @@ -683,11 +704,47 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetVsyncEnabled(int32_t enabled) {
>  HWC2::Error DrmHwcTwo::HwcDisplay::ValidateDisplay(uint32_t *num_types,
>                                                     uint32_t *num_requests) {
>    supported(__func__);
> +  size_t plane_count = 0;
>    *num_types = 0;
>    *num_requests = 0;
> +  size_t avail_planes = primary_planes_.size() + overlay_planes_.size();
> +
> +  HWC2::Error ret;
> +
> +  for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_)
> +    l.second.set_validated_type(HWC2::Composition::Invalid);
> +
> +  ret = CreateComposition(true);
> +  if (ret != HWC2::Error::None)
> +    // Assume the test failed due to overlay planes
> +    avail_planes = 1;
> +
> +  std::map<uint32_t, DrmHwcTwo::HwcLayer *> z_map;
> +  for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
> +    if (l.second.sf_type() == HWC2::Composition::Device)
> +        z_map.emplace(std::make_pair(l.second.z_order(), &l.second));
> +  }
> +
> +  /*
> +   * If more layers then planes, save one plane
> +   * for client composited layers
> +   */
> +  if (avail_planes < layers_.size())
> +       avail_planes--;
> +
> +  for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
> +    if (!avail_planes--)
> +        break;
> +    l.second->set_validated_type(HWC2::Composition::Device);
> +  }
> +
>    for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
>      DrmHwcTwo::HwcLayer &layer = l.second;
>      switch (layer.sf_type()) {
> +      case HWC2::Composition::Device:
> +        if (layer.validated_type() == HWC2::Composition::Device)
> +          break;
> +        // fall thru
>        case HWC2::Composition::SolidColor:
>        case HWC2::Composition::Cursor:
>        case HWC2::Composition::Sideband:
> diff --git a/drmhwctwo.h b/drmhwctwo.h
> index 0490e2ac7f85..bbf55d9a08bc 100644
> --- a/drmhwctwo.h
> +++ b/drmhwctwo.h
> @@ -171,6 +171,7 @@ class DrmHwcTwo : public hwc2_device_t {
>                                     float *min_luminance);
>      HWC2::Error GetReleaseFences(uint32_t *num_elements, hwc2_layer_t *layers,
>                                   int32_t *fences);
> +    HWC2::Error CreateComposition(bool test);

This is more of a private function than a HWC2 hook.

>      HWC2::Error PresentDisplay(int32_t *retire_fence);
>      HWC2::Error SetActiveConfig(hwc2_config_t config);
>      HWC2::Error SetClientTarget(buffer_handle_t target, int32_t acquire_fence,
> --
> 2.17.0
>

Thanks for working on this! Fixup for the nits above:

https://gitlab.freedesktop.org/stschake/drm-hwcomposer/commit/3aa0eb88

Took a short look at isolating the composition, too, but it's pretty
interwoven with the layer state.

Regards,
Stefan


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