[igt-dev] [PATCH i-g-t 2/2] lib/i915/intel_memory_region: Add fallback for creating gem bo

[Zbigniew Kempczyński]

For stable kernels we get -ENODEV on integrated where gem_create_ext()
call tries to allocate bo in system memory. Instead of asserting this
case we can fallback to gem_create() as this allocation can be resolved
using legacy call.

Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
Cc: Petri Latvala <petri.latvala at intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit at intel.com>
---
 lib/i915/intel_memory_region.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/i915/intel_memory_region.c b/lib/i915/intel_memory_region.c
index fd29eec90..2263f1984 100644
--- a/lib/i915/intel_memory_region.c
+++ b/lib/i915/intel_memory_region.c
@@ -197,8 +197,23 @@ int __gem_create_in_memory_region_list(int fd, uint32_t *handle, uint64_t *size,
 		.num_regions = num_regions,
 		.regions = to_user_pointer(mem_regions),
 	};
+	int ret;
 
-	return __gem_create_ext(fd, size, handle, &ext_regions.base);
+	ret = __gem_create_ext(fd, size, handle, &ext_regions.base);
+
+	/*
+	 * Provide fallback for stable kernels if region passed in the array
+	 * can be system memory. In this case we get -ENODEV but still
+	 * we're able to allocate gem bo in system memory using legacy call.
+	 */
+	if (ret == -ENODEV)
+		for (int i = 0; i < num_regions; i++)
+			if (mem_regions[i].memory_class == I915_MEMORY_CLASS_SYSTEM) {
+				ret = __gem_create(fd, size, handle);
+				break;
+			}
+
+	return ret;
 }
 
 /* gem_create_in_memory_region_list:
-- 
2.26.0