We've made the choice not to use fast clears on layer > 0 with multilayer images. This is partly because we would need to store multiple clear colors for each layer, making the existing memory layout, already including aux surfaces, fast clear color, image state, etc... even more complex.
Partial resolves are the operations transfering the clear colors into the auxiliary buffers. This operation is currently implemented in Blorp by loading the clear color from the image's BO, into a shader that then samples from the auxiliary buffer and writes the color only if it isn't there already.
The problem here is that because we store only one clear color for all layers and it is used for partial resolves. If you trigger a partial clear on a layer > 0, then you're likely to deal with a color that is not what you actually want. In the particular issues below, we have multiple layers, each cleared with a different color but the partial resolve just writes the wrong color into the auxiliary buffers for layers > 0.
Signed-off-by: Lionel Landwerlin lionel.g.landwerlin@intel.com Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108910 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108911 Cc: mesa-stable@lists.freedesktop.org