From 9be05b57bd9152b7c26b1599b87aeb42a102f0cf Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sun, 25 Jun 2006 05:48:23 -0700 Subject: [PATCH] rtc: small documentation update Rtc driver documentation update * Mention the max-user-freq control file. * Add missing header in example code. Signed-off-by: Jean Delvare Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/rtc.txt | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'Documentation/rtc.txt') diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt index 95d17b3e2eee..2a58f985795a 100644 --- a/Documentation/rtc.txt +++ b/Documentation/rtc.txt @@ -44,8 +44,10 @@ normal timer interrupt, which is 100Hz. Programming and/or enabling interrupt frequencies greater than 64Hz is only allowed by root. This is perhaps a bit conservative, but we don't want an evil user generating lots of IRQs on a slow 386sx-16, where it might have -a negative impact on performance. Note that the interrupt handler is only -a few lines of code to minimize any possibility of this effect. +a negative impact on performance. This 64Hz limit can be changed by writing +a different value to /proc/sys/dev/rtc/max-user-freq. Note that the +interrupt handler is only a few lines of code to minimize any possibility +of this effect. Also, if the kernel time is synchronized with an external source, the kernel will write the time back to the CMOS clock every 11 minutes. In @@ -81,6 +83,7 @@ that will be using this driver. */ #include +#include #include #include #include -- cgit v1.2.3