drm/panthor: Don't check the array stride on empty uobj arrays

The user is likely to leave all the drm_panthor_obj_array fields
to zero when the array is empty, which will cause an EINVAL failure.

v2:
- Added R-bs

Fixes: 4bdca1150792 ("drm/panthor: Add the driver frontend block")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240703071640.231278-2-boris.brezillon@collabora.com

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index b8a84f26b3ef847b5662e6fc2fa50431962c76c5..b5e7b919f241e4b3010c3953c9ecdee5086cb770 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -86,15 +86,15 @@ panthor_get_uobj_array(const struct drm_panthor_obj_array *in, u32 min_stride,
        int ret = 0;
        void *out_alloc;
 
+       if (!in->count)
+               return NULL;
+
        /* User stride must be at least the minimum object size, otherwise it might
         * lack useful information.
         */
        if (in->stride < min_stride)
                return ERR_PTR(-EINVAL);
 
-       if (!in->count)
-               return NULL;
-
        out_alloc = kvmalloc_array(in->count, obj_size, GFP_KERNEL);
        if (!out_alloc)
                return ERR_PTR(-ENOMEM);