![Ivan Kokshaysky](/assets/img/avatar_default.png)
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>
17 lines
371 B
C
17 lines
371 B
C
#ifndef _ALPHA_RTC_H
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#define _ALPHA_RTC_H
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#if defined(CONFIG_ALPHA_GENERIC)
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# define get_rtc_time alpha_mv.rtc_get_time
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# define set_rtc_time alpha_mv.rtc_set_time
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#else
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# if defined(CONFIG_ALPHA_MARVEL) && defined(CONFIG_SMP)
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# define get_rtc_time marvel_get_rtc_time
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# define set_rtc_time marvel_set_rtc_time
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# endif
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#endif
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#include <asm-generic/rtc.h>
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#endif
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