power_supply: bump EC version check that we refuse to run with in olpc_battery

Refuse to run with an EC < 0x44.  We're playing it safe, and this is a pretty
old EC version.

Also, add a comment about why we're checking the EC version.

Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/power/olpc_battery.c b/drivers/power/olpc_battery.c
index d5fe6f0c9de0..c8b596a7fc94 100644
--- a/drivers/power/olpc_battery.c
+++ b/drivers/power/olpc_battery.c
@@ -389,8 +389,14 @@ static int __init olpc_bat_init(void)
 
         if (!olpc_platform_info.ecver)
                 return -ENXIO;
-        if (olpc_platform_info.ecver < 0x43) {
-                printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver);
+
+        /*
+         * We've seen a number of EC protocol changes; this driver requires
+         * the latest EC protocol, supported by 0x44 and above.
+         */
+        if (olpc_platform_info.ecver < 0x44) {
+                printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
+                        "battery driver.\n", olpc_platform_info.ecver);
                 return -ENXIO;
         }