On 8/3/2023 06:28, Andi Shyti wrote:
Hi John,
On Wed, Aug 02, 2023 at 11:49:40AM -0700, John.C.Harrison@xxxxxxxxx wrote:
From: John Harrison <John.C.Harrison@xxxxxxxxx>
It was noticed that if the very first 'stealing' request failed to
create for some reason then the 'steal all ids' loop would immediately
exit with 'last' still being NULL. The test would attempt to continue
but using a null pointer. Fix that by aborting the test if it fails to
create any requests at all.
Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/uc/selftest_guc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/selftest_guc.c b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
index 1fd760539f77b..bfb72143566f6 100644
--- a/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
+++ b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
@@ -204,9 +204,9 @@ static int intel_guc_steal_guc_ids(void *arg)
if (IS_ERR(rq)) {
ret = PTR_ERR(rq);
rq = NULL;
- if (ret != -EAGAIN) {
- guc_err(guc, "Failed to create request %d: %pe\n",
- context_index, ERR_PTR(ret));
+ if ((ret != -EAGAIN) || !last) {
isn't last alway NULL here?
Andi
No, only on the first pass around the loop. When a request is
successfully created, the else clause below assigns last to that new
request. So if the failure to create only happens on pass 2 or later,
last will be non-null. Which is the whole point of the code. It keeps
creating all the contexts/requests that it can until it runs out of
resources and gets an EAGAIN failure. At which point, last will be
pointing to the last successful creation and the test continues to the
next part of actually stealing an id.
But if the EAGAIN failure happens on the first pass then last will be
null and it is not safe/valid to proceed so it needs to abort. And if
anything other than EAGAIN is returned then something has gone wrong and
it doesn't matter what last is set to, it needs to abort regardless.
John.
+ guc_err(guc, "Failed to create %srequest %d: %pe\n",
+ last ? "" : "first ", context_index, ERR_PTR(ret));
goto err_spin_rq;
}
} else {
--
2.39.1
