linux/arch/alpha
Ivan Kokshaysky 5f7dc5d750 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>
2009-01-15 16:39:40 -08:00
..
boot inflate: refactor inflate malloc code 2008-07-25 10:53:28 -07:00
include/asm alpha: fix RTC on marvel 2009-01-15 16:39:40 -08:00
kernel alpha: fix RTC on marvel 2009-01-15 16:39:40 -08:00
lib remove __attribute_used__ 2008-01-28 23:21:18 +01:00
math-emu alpha: fix conversion from denormal float to double 2008-01-17 15:38:59 -08:00
mm alpha: use generic show_mem() 2008-07-26 12:00:10 -07:00
oprofile oprofile: more whitespace fixes 2008-10-15 20:55:51 +02:00
defconfig alpha/parisc: remove config variable DEBUG_RWLOCK 2008-02-06 10:41:03 -08:00
Kconfig container freezer: implement freezer cgroup subsystem 2008-10-20 08:52:34 -07:00
Kconfig.debug alpha/parisc: remove config variable DEBUG_RWLOCK 2008-02-06 10:41:03 -08:00
Makefile alpha: link failure fix 2008-06-20 16:46:10 -07:00