rtc regression [463a86304cae ("char/genrtc: x86: remove remnants of asm/rtc.h")]

[Ville Syrjälä]

Hi,

commit 463a86304cae ("char/genrtc: x86: remove remnants of asm/rtc.h")
broke rtc for me. Neither hwclock or rtcwake work anymore. This is just
a very standard x86-64 IVB box, and it was reported that machines in
our i915 test farm are having rtc related problems as well.

The first time I run hwclock after rebooting I get this:
 open("/dev/rtc", O_RDONLY)              = 3
 ioctl(3, PHN_SET_REGS or RTC_UIE_ON, 0) = 0
 select(4, [3], NULL, NULL, {10, 0})     = 0 (Timeout)
 ioctl(3, PHN_NOT_OH or RTC_UIE_OFF, 0)  = 0
 close(3)                                = 0

On all subsequent runs I get this:
 open("/dev/rtc", O_RDONLY)              = 3
 ioctl(3, PHN_SET_REGS or RTC_UIE_ON, 0) = -1 EINVAL (Invalid argument)
 ioctl(3, RTC_RD_TIME, 0x7ffd76b3ae70)   = -1 EINVAL (Invalid argument)
 close(3)                                = 0

463a86304cae^ gets me back to working condition:
 open("/dev/rtc", O_RDONLY)              = 3
 ioctl(3, PHN_SET_REGS or RTC_UIE_ON, 0) = 0
 select(4, [3], NULL, NULL, {10, 0})     = 1 (in [3], left {9, 530998})
 ioctl(3, PHN_NOT_OH or RTC_UIE_OFF, 0)  = 0
 ioctl(3, RTC_RD_TIME, {tm_sec=20, tm_min=17, tm_hour=15, tm_mday=9, tm_mon=7, tm_year=116, ...}) = 0
 close(3)                                = 0

-- 
Ville Syrjälä
Intel OTC