From f2411da746985e60d4d087f3a43e271c61785927 Mon Sep 17 00:00:00 2001 From: Luis R. Rodriguez Date: Mon, 30 Mar 2015 16:20:05 -0700 Subject: driver-core: add driver module asynchronous probe support Some init systems may wish to express the desire to have device drivers run their probe() code asynchronously. This implements support for this and allows userspace to request async probe as a preference through a generic shared device driver module parameter, async_probe. Implementation for async probe is supported through a module parameter given that since synchronous probe has been prevalent for years some userspace might exist which relies on the fact that the device driver will probe synchronously and the assumption that devices it provides will be immediately available after this. Signed-off-by: Luis R. Rodriguez Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- kernel/module.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 24d1f31d02f2..ea941bc327d5 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3107,7 +3107,7 @@ static noinline int do_init_module(struct module *mod) * * http://thread.gmane.org/gmane.linux.kernel/1420814 */ - if (current->flags & PF_USED_ASYNC) + if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC)) async_synchronize_full(); mutex_lock(&module_mutex); @@ -3240,8 +3240,16 @@ out: static int unknown_module_param_cb(char *param, char *val, const char *modname, void *arg) { + struct module *mod = arg; + int ret; + + if (strcmp(param, "async_probe") == 0) { + mod->async_probe_requested = true; + return 0; + } + /* Check for magic 'dyndbg' arg */ - int ret = ddebug_dyndbg_module_param_cb(param, val, modname); + ret = ddebug_dyndbg_module_param_cb(param, val, modname); if (ret != 0) pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); return 0; -- cgit v1.2.3-55-g7522