[PATCH] selftests/gpio: skip when gpio-mockup is not available

[Eva Kurchatova]

The test drives the gpio-mockup debugfs interface, but checks only that
debugfs is mounted. On a kernel built without the driver every case
fails on a missing device rather than reporting that the driver is not
there:

  # ls: cannot access '/sys/kernel/debug/gpio-mockup': No such file
  # GPIO gpio-mockup test FAIL

Skip instead. Accept the driver either as a module modinfo can find, or
as one already loaded or built in, which /sys/module/gpio-mockup reports;
the test runs perfectly well in the built-in case.

Signed-off-by: Eva Kurchatova <eva.kurchatova@xxxxxxxxxxxxx>
---
 tools/testing/selftests/gpio/gpio-mockup.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/gpio/gpio-mockup.sh b/tools/testing/selftests/gpio/gpio-mockup.sh
index fc2dd4c24d06..b13ccecd4a71 100755
--- a/tools/testing/selftests/gpio/gpio-mockup.sh
+++ b/tools/testing/selftests/gpio/gpio-mockup.sh
@@ -51,6 +51,9 @@ prerequisite()
 	DEBUGFS=$(grep -w debugfs /proc/mounts | cut -f2 -d' ')
 	[ -d "$DEBUGFS" ] || skip "debugfs is not mounted"
 
+	modinfo $module >/dev/null 2>&1 || [ -d /sys/module/$module ] ||
+		skip "$module module is not available"
+
 	GPIO_DEBUGFS=$DEBUGFS/$module
 }
 
-- 
2.55.0