[igt-dev] [PATCH i-g-t 1/2] lib/igt_kmod: Wait for a kmod to finish its probe before unloding it.

[Daniele Ceraolo Spurio]

Modprobing i915 can result in other dependent modules being loaded
automatically as a follow up. This means that by the time the i915
load function returns these modules may still be going through their
init, so if we try to immediately unload i915 again we will fail with
an -EBUSY. To avoid this, if the module load is still in progress, wait
for it to complete before unloading.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 lib/igt_kmod.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
index cf7a3b22..d2ac8a56 100644
--- a/lib/igt_kmod.c
+++ b/lib/igt_kmod.c
@@ -143,6 +143,12 @@ out:
 	return ret;
 }
 
+static bool
+igt_kmod_is_loading(struct kmod_module *kmod)
+{
+	return kmod_module_get_initstate(kmod) == KMOD_MODULE_COMING;
+}
+
 static int modprobe(struct kmod_module *kmod, const char *options)
 {
 	unsigned int flags;
@@ -289,6 +295,16 @@ igt_kmod_unload(const char *mod_name, unsigned int flags)
 		goto out;
 	}
 
+	if (igt_kmod_is_loading(kmod)) {
+		igt_debug("%s still initializing\n", mod_name);
+		err = igt_wait(!igt_kmod_is_loading(kmod), 10000, 100);
+		if (err < 0) {
+			igt_debug("%s failed to complete init within the timeout\n",
+				  mod_name);
+			goto out;
+		}
+	}
+
 	err = igt_kmod_unload_r(kmod, flags);
 	if (err < 0) {
 		igt_debug("Could not remove module %s (%s)\n", mod_name,
-- 
2.25.1