gpu: nvgpu: vgpu: fix Oops when dt have no mempool-fecs-trace

Avoid unreserving mempool when it didn't reserve successfully.

Bug 1757733

Change-Id: I39d36492a54c2e71afff3221505196a463c06776
Signed-off-by: Richard Zhao <rizhao@nvidia.com>
Reviewed-on: http://git-master/r/1132057
(cherry picked from commit b18060ea30b924c4ef39c05a70d4f03759061128)
Reviewed-on: http://git-master/r/1132129
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/fecs_trace_vgpu.c b/drivers/gpu/nvgpu/vgpu/fecs_trace_vgpu.c
index 02e0baad..bd1a7451 100644
--- a/drivers/gpu/nvgpu/vgpu/fecs_trace_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/fecs_trace_vgpu.c
@@ -58,6 +58,7 @@ static int vgpu_fecs_trace_init(struct gk20a *g)
         if (IS_ERR(vcst->cookie)) {
                 dev_info(dev_from_gk20a(g),
                         "mempool  %u reserve failed\n", mempool);
+                vcst->cookie = NULL;
                 err = -EINVAL;
                 goto fail;
         }
@@ -85,7 +86,7 @@ static int vgpu_fecs_trace_init(struct gk20a *g)
         return 0;
 fail:
         iounmap(vcst->buf);
-        if (!IS_ERR(vcst->cookie))
+        if (vcst->cookie)
                 tegra_hv_mempool_unreserve(vcst->cookie);
         kfree(vcst);
         return err;