[igt-dev] [PATCH i-g-t v2 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.

v2: move the wait to igt_kmod_unload_r (Ashutosh)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit at intel.com>
---
 lib/igt_kmod.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
index cf7a3b22..0e3ca9b3 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;
@@ -261,6 +267,17 @@ static int igt_kmod_unload_r(struct kmod_module *kmod, unsigned int flags)
 	if (err < 0)
 		return err;
 
+	if (igt_kmod_is_loading(kmod)) {
+		const char *mod_name = kmod_module_get_name(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);
+			return err;
+		}
+	}
+
 	return kmod_module_remove_module(kmod, flags);
 }
 
-- 
2.25.1