[Mesa-dev] [Bug 105396] tc compatible htile sets depth of htiles of discarded fragments to 1.0

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=105396

            Bug ID: 105396
           Summary: tc compatible htile sets depth of htiles of discarded
                    fragments to 1.0
           Product: Mesa
           Version: git
          Hardware: Other
                OS: All
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Drivers/Vulkan/radeon
          Assignee: mesa-dev at lists.freedesktop.org
          Reporter: jlegg at feralinteractive.com
        QA Contact: mesa-dev at lists.freedesktop.org

Created attachment 137887
  --> https://bugs.freedesktop.org/attachment.cgi?id=137887&action=edit
Renderdoc v1.0 capture

On RADV, when using a VK_FORMAT_D32_SFLOAT (or VK_FORMAT_D32_SFLOAT_S8_UINT)
depth buffer cleared to 0.0, if a fragment shader discards all fragments in a
cleared htile, the htile's depth can be set to 1.0, instead of keeping the
clear value of 0.0.

The attached renderdoc capture reproduces the issue by clearing the depth
buffer to 0.0 with vkCmdClearAttachments, then drawing a triangle in the upper
left half of an image using a shader which discards fragments that lie outside
of a semicircle. The bug doesn't reproduce if I remove the
vkCmdClearAttachments and use VK_LOAD_OP_CLEAR at the start of the render pass.
However I have another more complex application which appears to be using
VK_LOAD_OP_CLEAR in an earlier renderpass and loading stored depth values in a
renderpass which reproduces this bug, without using other clears in the middle.

I'm using git revision fb5825e7ceeb16ac05f870ffe1e5a5daa09e68dd on an AMD RX
480.
Setting RADV_DEBUG to nohiz or nofastclears avoids the bug.

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20180308/f031fdd8/attachment.html>