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authorDavid P. Reed <dpreed@reed.com>2008-02-17 16:56:39 -0500
committerIngo Molnar <mingo@elte.hu>2008-04-17 17:40:47 +0200
commit04aaa7ba096c707a8df337b29303f1a5a65f0462 (patch)
tree154940ae375efc082f7a52116963e24d42b423f6 /arch
parent03ae5768b6110ebaa97dc3e7abf1c3d8bec5f874 (diff)
x86: fix cmos read and write to not use inb_p and outb_p
fix code to access CMOS rtc registers so that it does not use inb_p and outb_p routines, which are deprecated. Extensive research on all known CMOS RTC chipset timing shows that there is no need for a delay in accessing the registers of these chips even on old machines. These chipa are never on an expansion bus, but have always been "motherboard" resources, either in the processor chipset or explicitly on the motherboard, and they are not part of the ISA/LPC or PCI buses, so delays should not be based on bus timing. The reason to fix it: 1) port 80 writes often hang some laptops that use ENE EC chipsets, esp. those designed and manufactured by Quanta for HP; 2) RTC accesses are timing sensitive, and extra microseconds may matter; 3) the new "io_delay" function is calibrated by expansion bus timing needs, thus is not appropriate for access to CMOS rtc registers. Signed-off-by: David P. Reed <dpreed@reed.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/rtc.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 91492190ac72..9615eee9b775 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -146,8 +146,8 @@ unsigned char rtc_cmos_read(unsigned char addr)
unsigned char val;
lock_cmos_prefix(addr);
- outb_p(addr, RTC_PORT(0));
- val = inb_p(RTC_PORT(1));
+ outb(addr, RTC_PORT(0));
+ val = inb(RTC_PORT(1));
lock_cmos_suffix(addr);
return val;
}
@@ -156,8 +156,8 @@ EXPORT_SYMBOL(rtc_cmos_read);
void rtc_cmos_write(unsigned char val, unsigned char addr)
{
lock_cmos_prefix(addr);
- outb_p(addr, RTC_PORT(0));
- outb_p(val, RTC_PORT(1));
+ outb(addr, RTC_PORT(0));
+ outb(val, RTC_PORT(1));
lock_cmos_suffix(addr);
}
EXPORT_SYMBOL(rtc_cmos_write);