[Intel-gfx] [PATCH i-g-t] tools/intel_gpu_top: Restore user friendly error message

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

We have a nice error message displayed when an user with insufficient
permissions tries to run the tool, but that got lost while Meteorlake
support was added. Bring it back in.

v2:
 * Propagate unexpected errno on multi-tile systems too. (Umesh)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
---
 tools/intel_gpu_top.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
index 87e9681e53b4..10601e66b18e 100644
--- a/tools/intel_gpu_top.c
+++ b/tools/intel_gpu_top.c
@@ -554,9 +554,9 @@ static int get_num_gts(uint64_t type)
 
 		close(fd);
 	}
-	assert(!errno || errno == ENOENT);
-	assert(cnt > 0);
-	errno = 0;
+
+	if (!cnt || (errno && errno != ENOENT))
+		cnt = -errno;
 
 	return cnt;
 }
@@ -590,6 +590,8 @@ static int pmu_init(struct engines *engines)
 	engines->fd = -1;
 	engines->num_counters = 0;
 	engines->num_gts = get_num_gts(type);
+	if (engines->num_gts <= 0)
+		return -1;
 
 	engines->irq.config = I915_PMU_INTERRUPTS;
 	fd = _open_pmu(type, engines->num_counters, &engines->irq, engines->fd);
-- 
2.39.2