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authorIvan Kokshaysky <ink@jurassic.park.msu.ru>2009-01-15 13:51:19 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-15 16:39:40 -0800
commit5f7dc5d75076fd1c1fc6bc09f2467509d20db24a (patch)
treec105f8463607381acd7d02bdda75641b3f497e37 /arch/alpha/kernel/time.c
parent2f88d151cb8e73587983d7feccd70672ff6730fe (diff)
alpha: fix RTC on marvel
Unlike other alphas, marvel doesn't have real PC-style CMOS clock hardware - RTC accesses are emulated via PAL calls. Unfortunately, for unknown reason these calls work only on CPU #0. So current implementation for arbitrary CPU makes CMOS_READ/WRITE to be executed on CPU #0 via IPI. However, for obvious reason this doesn't work with standard get/set_rtc_time() functions, where a bunch of CMOS accesses is done with disabled interrupts. Solved by making the IPI calls for entire get/set_rtc_time() functions, not for individual CMOS accesses. Which is also a lot more effective performance-wise. The patch is largely based on the code from Jay Estabrook. My changes: - tweak asm-generic/rtc.h by adding a couple of #defines to avoid a massive code duplication in arch/alpha/include/asm/rtc.h; - sys_marvel.c: fix get/set_rtc_time() return values (Jay's FIXMEs). NOTE: this fixes *only* LIB_RTC drivers. Legacy (CONFIG_RTC) driver wont't work on marvel. Actually I think that we should just disable CONFIG_RTC on alpha (maybe in 2.6.30?), like most other arches - AFAIK, all modern distributions use LIB_RTC anyway. Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/alpha/kernel/time.c')
-rw-r--r--arch/alpha/kernel/time.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index e6a231435cba..b04e2cbf23a4 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -46,6 +46,7 @@
#include <asm/io.h>
#include <asm/hwrpb.h>
#include <asm/8253pit.h>
+#include <asm/rtc.h>
#include <linux/mc146818rtc.h>
#include <linux/time.h>
@@ -180,6 +181,15 @@ common_init_rtc(void)
init_rtc_irq();
}
+unsigned int common_get_rtc_time(struct rtc_time *time)
+{
+ return __get_rtc_time(time);
+}
+
+int common_set_rtc_time(struct rtc_time *time)
+{
+ return __set_rtc_time(time);
+}
/* Validate a computed cycle counter result against the known bounds for
the given processor core. There's too much brokenness in the way of