[PATCH] olpc-ec: initialise earlier

[PATCH] olpc-ec: initialise earlier

[Daniel Drake]

Being a low-level component, various drivers (e.g. olpc-battery) assume that
it is ok to communicate with the OLPC Embedded Controller during probe.
Therefore the OLPC EC driver must be initialised before other drivers try to
use it. This was the case until it was recently moved out of arch/x86 and
restructured.

Use arch_initcall so that olpc-ec is readied earlier, matching the
previous behaviour. Fixes various drivers such as olpc-battery and
olpc-xo1-sci.

Signed-off-by: Daniel Drake <dsd@laptop.org>
---
 drivers/platform/olpc/olpc-ec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/olpc/olpc-ec.c b/drivers/platform/olpc/olpc-ec.c
index 0f9f859..f911952 100644
--- a/drivers/platform/olpc/olpc-ec.c
+++ b/drivers/platform/olpc/olpc-ec.c
@@ -330,7 +330,7 @@ static int __init olpc_ec_init_module(void)
 	return platform_driver_register(&olpc_ec_plat_driver);
 }
 
-module_init(olpc_ec_init_module);
+arch_initcall(olpc_ec_init_module);
 
 MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
 MODULE_LICENSE("GPL");
-- 
1.8.3.1

Re: [PATCH] olpc-ec: initialise earlier

[Andrew Morton]

On Sat, 10 Aug 2013 15:22:15 -0400 (EDT) Daniel Drake <dsd@laptop.org> wrote:

> Being a low-level component, various drivers (e.g. olpc-battery) assume that
> it is ok to communicate with the OLPC Embedded Controller during probe.
> Therefore the OLPC EC driver must be initialised before other drivers try to
> use it. This was the case until it was recently moved out of arch/x86 and
> restructured.
> 
> Use arch_initcall so that olpc-ec is readied earlier, matching the
> previous behaviour. Fixes various drivers such as olpc-battery and
> olpc-xo1-sci.
> 

You imply that there was a regression, but don't describe the
user-visible effects of the regression.

You provide hints which would permit me, with sufficient effort, to
approximately work out which kernel versions were affected by the
regression and then left it at that.

I need to work out which kernel version(s) need patching, and why. 
Please, make it easier for me!