4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx> [ 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@xxxxxxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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);