[igt-dev] [PATCH] tools/intel_gpu_top: Return the error to the caller of pmu_init

[Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>]

When run as a regular user, we see an assert instead of a proper error
message.  Propagate errors correctly to caller.

Link: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/139
Fixes: (c67825ba40de: intel_gpu_top: Determine number of tiles)
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
---
 tools/intel_gpu_top.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
index 7018499c..24fba88b 100644
--- a/tools/intel_gpu_top.c
+++ b/tools/intel_gpu_top.c
@@ -536,7 +536,7 @@ static void imc_reads_open(struct pmu_counter *pmu, struct engines *engines)
 	imc_open(pmu, "data_reads", engines);
 }
 
-static int get_num_gts(uint64_t type)
+static int get_num_gts(uint64_t type, int *num_gts)
 {
 	int fd, cnt;
 
@@ -548,11 +548,13 @@ static int get_num_gts(uint64_t type)
 
 		close(fd);
 	}
-	assert(!errno || errno == ENOENT);
+	if (errno && errno != ENOENT)
+		return fd;
+
 	assert(cnt > 0);
-	errno = 0;
+	*num_gts = cnt;
 
-	return cnt;
+	return 0;
 }
 
 static void init_aggregate_counters(struct engines *engines)
@@ -578,12 +580,14 @@ static void init_aggregate_counters(struct engines *engines)
 static int pmu_init(struct engines *engines)
 {
 	unsigned int i;
-	int fd;
+	int fd, ret;
 	uint64_t type = igt_perf_type_id(engines->device);
 
 	engines->fd = -1;
 	engines->num_counters = 0;
-	engines->num_gts = get_num_gts(type);
+	ret = get_num_gts(type, &engines->num_gts);
+	if (ret)
+		return ret;
 
 	engines->irq.config = I915_PMU_INTERRUPTS;
 	fd = _open_pmu(type, engines->num_counters, &engines->irq, engines->fd);
-- 
2.34.1