[Intel-gfx] [PATCH 4/4] drm/i915/guc: Don't go bang in GuC log if no GuC

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

If the GuC has failed to load for any reason and then the user pokes
the debugfs GuC log interface, a BUG and/or null pointer deref can
occur. Don't let that happen.

Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c
index da7dd099fd93..140896bb988b 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c
@@ -79,7 +79,7 @@ static int guc_log_level_get(void *data, u64 *val)
 {
 	struct intel_guc_log *log = data;
 
-	if (!intel_guc_is_used(log_to_guc(log)))
+	if (!log->vma)
 		return -ENODEV;
 
 	*val = intel_guc_log_get_level(log);
@@ -91,7 +91,7 @@ static int guc_log_level_set(void *data, u64 val)
 {
 	struct intel_guc_log *log = data;
 
-	if (!intel_guc_is_used(log_to_guc(log)))
+	if (!log->vma)
 		return -ENODEV;
 
 	return intel_guc_log_set_level(log, val);
-- 
2.25.1