From 4469887f863aa5348cc95b77a6e4b1e83a7fc6cd Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Thu, 14 Feb 2013 18:14:27 +0000 Subject: [PATCH] drivercore: Fix ordering between deferred_probe and exiting initcalls commit d72cca1eee5b26e313da2a380d4862924e271031 upstream. One of the side effects of deferred probe is that some drivers which used to be probed before initcalls completed are now happening slightly later. This causes two problems. - If a console driver gets deferred, then it may not be ready when userspace starts. For example, if a uart depends on pinctrl, then the uart will get deferred and /dev/console will not be available - __init sections will be discarded before built-in drivers are probed. Strictly speaking, __init functions should not be called in a drivers __probe path, but there are a lot of drivers (console stuff again) that do anyway. In the past it was perfectly safe to do so because all built-in drivers got probed before the end of initcalls. This patch fixes the problem by forcing the first pass of the deferred list to complete at late_initcall time. This is late enough to catch the drivers that are known to have the above issues. Signed-off-by: Grant Likely Tested-by: Haojian Zhuang Cc: Arnd Bergmann Cc: Russell King Cc: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index e3bbed8a617c..61d3e1b40694 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -172,6 +172,8 @@ static int deferred_probe_initcall(void) driver_deferred_probe_enable = true; driver_deferred_probe_trigger(); + /* Sort as many dependencies as possible before exiting initcalls */ + flush_workqueue(deferred_wq); return 0; } late_initcall(deferred_probe_initcall); -- 2.39.5