[igt-dev] [PATCH i-g-t] lib/i915: Handle QUERY_MEMORY_REGIONS on older kernels

[Bhanuprakash Modem]

While checking for LMEM support on older kernels with the
DRM_I915_QUERY_MEMORY_REGIONS, it may fail with EINVAL.

Instead of abort/asserting the test, we must handle this
case properly.

Cc: Ashutosh Dixit <ashutosh.dixit at intel.com>
Cc: Vidya Srinivas <vidya.srinivas at intel.com>
Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
---
 lib/i915/intel_memory_region.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/i915/intel_memory_region.c b/lib/i915/intel_memory_region.c
index 144ae12ca..51e50471f 100644
--- a/lib/i915/intel_memory_region.c
+++ b/lib/i915/intel_memory_region.c
@@ -114,17 +114,19 @@ uint32_t gem_get_batch_size(int fd, uint8_t mem_region_type)
 struct drm_i915_query_memory_regions *gem_get_query_memory_regions(int fd)
 {
 	struct drm_i915_query_item item;
-	struct drm_i915_query_memory_regions *query_info;
+	struct drm_i915_query_memory_regions *query_info = NULL;
 
 	memset(&item, 0, sizeof(item));
 	item.query_id = DRM_I915_QUERY_MEMORY_REGIONS;
-	i915_query_items(fd, &item, 1);
+	if (__i915_query_items(fd, &item, 1) || item.length < 0)
+		goto out;
 
 	query_info = calloc(1, item.length);
 
 	item.data_ptr = to_user_pointer(query_info);
 	i915_query_items(fd, &item, 1);
 
+out:
 	return query_info;
 }
 
@@ -143,6 +145,9 @@ uint8_t gem_get_lmem_region_count(int fd)
 	uint8_t lmem_regions = 0;
 
 	query_info = gem_get_query_memory_regions(fd);
+	if (!query_info)
+		goto out;
+
 	num_regions = query_info->num_regions;
 
 	for (int i = 0; i < num_regions; i++) {
@@ -151,6 +156,7 @@ uint8_t gem_get_lmem_region_count(int fd)
 	}
 	free(query_info);
 
+out:
 	return lmem_regions;
 }
 
-- 
2.32.0