[v14,10/12] drm/ttm/tests: Add TODO file

Commit Message

Karolina Stolarek June 12, 2024, 12:03 p.m. UTC

List improvements for the test suite with some notes.

Signed-off-by: Karolina Stolarek <[e-mail]>
Reviewed-by: Thomas Hellström <[e-mail]>
---
 drivers/gpu/drm/ttm/tests/TODO | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 drivers/gpu/drm/ttm/tests/TODO

Patch

diff --git a/drivers/gpu/drm/ttm/tests/TODO b/drivers/gpu/drm/ttm/tests/TODO
new file mode 100644
index 000000000000..45b03d184ccf
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/TODO
@@ -0,0 +1,27 @@ 
+TODO
+=====
+
+- Add a test case where the only evictable BO is busy
+- Update eviction tests so they use parametrized "from" memory type
+- Improve mock manager's implementation, e.g. allocate a block of
+  dummy memory that can be used when testing page mapping functions
+- Suggestion: Add test cases with external BOs
+- Suggestion: randomize the number and size of tested buffers in
+  ttm_bo_validate()
+- Agree on the naming convention
+- Rewrite the mock manager: drop use_tt and manage mock memory using
+  drm_mm manager
+
+Notes and gotchas
+=================
+
+- These tests are built and run with a UML kernel, because
+  1) We are interested in hardware-independent testing
+  2) We don't want to have actual DRM devices interacting with TTM
+     at the same time as the test one. Getting these to work in
+     parallel would require some time (...and that's a "todo" in itself!)
+- Triggering ttm_bo_vm_ops callbacks from KUnit (i.e. kernel) might be
+  a challenge, but is worth trying. Look at selftests like
+  i915/gem/selftests/i915_gem_mman.c for inspiration
+- The test suite uses UML where ioremap() call returns NULL, meaning that
+  ttm_bo_ioremap() can't be tested, unless we find a way to stub it