[PATCH 3/6] drm/qxl: reject empty TTM memory ranges

[Jiale Yao <yaojiale02@163.com>]

A zero page count passed to the range manager reaches drm_mm_init()
and causes its zero-range BUG check to fire. Reject empty memory
ranges before initializing the manager.

Fixes: 37205891d84f ("drm/ttm: make ttm_range_man_init/takedown take type + args")
Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
 drivers/gpu/drm/qxl/qxl_ttm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/qxl/qxl_ttm.c b/drivers/gpu/drm/qxl/qxl_ttm.c
index 5d495c4798a3..c8cda805b645 100644
--- a/drivers/gpu/drm/qxl/qxl_ttm.c
+++ b/drivers/gpu/drm/qxl/qxl_ttm.c
@@ -185,6 +185,9 @@ static int qxl_ttm_init_mem_type(struct qxl_device *qdev,
 				 unsigned int type,
 				 uint64_t size)
 {
+	if (!size)
+		return -EINVAL;
+
 	return ttm_range_man_init(&qdev->mman.bdev, type, false, size);
 }
 
-- 
2.34.1