[PATCH 4.16 168/272] powerpc/vas: Fix cleanup when VAS is not configured

Greg Kroah-Hartman
2018-05-28T11:11:44Z

From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>

[ Upstream commit 45ddea8a73a25461387eb8e87f3e0ecca084799b ]

When VAS is not configured, unregister the platform driver. Also simplify
cleanup by delaying vas debugfs init until we know VAS is configured.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/platforms/powernv/vas-debug.c | 11 +++++++++++
arch/powerpc/platforms/powernv/vas.c | 6 +++---
2 files changed, 14 insertions(+), 3 deletions(-)

--- a/arch/powerpc/platforms/powernv/vas-debug.c
+++ b/arch/powerpc/platforms/powernv/vas-debug.c
@@ -179,6 +179,7 @@ void vas_instance_init_dbgdir(struct vas
{
struct dentry *d;

+ vas_init_dbgdir();
if (!vas_debugfs)
return;

@@ -201,8 +202,18 @@ free_name:
vinst->dbgdir = NULL;
}

+/*
+ * Set up the "root" VAS debugfs dir. Return if we already set it up
+ * (or failed to) in an earlier instance of VAS.
+ */
void vas_init_dbgdir(void)
{
+ static bool first_time = true;
+
+ if (!first_time)
+ return;
+
+ first_time = false;
vas_debugfs = debugfs_create_dir("vas", NULL);
if (IS_ERR(vas_debugfs))
vas_debugfs = NULL;
--- a/arch/powerpc/platforms/powernv/vas.c
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -160,8 +160,6 @@ static int __init vas_init(void)
int found = 0;
struct device_node *dn;

- vas_init_dbgdir();
-
platform_driver_register(&vas_driver);

for_each_compatible_node(dn, NULL, "ibm,vas") {
@@ -169,8 +167,10 @@ static int __init vas_init(void)
found++;
}

- if (!found)
+ if (!found) {
+ platform_driver_unregister(&vas_driver);
return -ENODEV;
+ }

pr_devel("Found %d instances\n", found);