https://bugs.freedesktop.org/show_bug.cgi?id=82671
Priority: medium Bug ID: 82671 Assignee: dri-devel@lists.freedesktop.org Summary: [r600g-evergreen][compute]Empty kernel execution causes crash Severity: normal Classification: Unclassified OS: Linux (All) Reporter: damien.hilloulin@supelec.fr Hardware: All Status: NEW Version: git Component: Drivers/Gallium/r600 Product: Mesa
Created attachment 104687 --> https://bugs.freedesktop.org/attachment.cgi?id=104687&action=edit Bug repro program source file
I gave a shot to opencl support on my evergreen card (cedar) with mesa git. I noticed that with an empty kernel the program crash with: evergreen_state.c:1827:evergreen_emit_vertex_buffers: Assertion `rbuffer' failed.
I made a little debugging and I think that this is du to a bug in evergreen_init_compute_state_functions from evergreen_compute.c .
The two concerned lines are
/* We always use at least one vertex buffer for parameters (id = 1)*/ ctx->cs_vertex_buffer_state.enabled_mask = ctx->cs_vertex_buffer_state.dirty_mask = 0x2;
With an empty kernel there is in fact no vertex buffer used as far as I can see.
By changing the two lines to ctx->cs_vertex_buffer_state.enabled_mask = ctx->cs_vertex_buffer_state.dirty_mask = 0x0;
It doesn't crash for me anymore. However I am a total driver development noob so my interpretation (and therefore fix) can be wrong.
You can find attacted the very small program to be able to cause the crash.