diff options
| author | Finn Thain <fthain@telegraphics.com.au> | 2018-04-23 11:02:57 +1000 |
|---|---|---|
| committer | Geert Uytterhoeven <geert@linux-m68k.org> | 2018-05-22 10:31:50 +0200 |
| commit | b65769fc013edb7c2e5fdcd91ea6124ad76168f5 (patch) | |
| tree | b6ad02cfbf7a81d1a4f339d0873fabb71b8b549e /arch/m68k/apollo | |
| parent | 4eee57d68b8b2e6e0a6960c0bacf93448e4ae214 (diff) | |
| download | linux-b65769fc013edb7c2e5fdcd91ea6124ad76168f5.tar.bz2 | |
m68k: Fix off-by-one calendar month
This fixes a bug in read_persistent_clock() which causes the system
clock to lag the Real Time Clock by one month. The problem was noticed
on a Mac, but theoretically it must also affect Atari, BVME6000 and Q40.
The tm_mon value in the struct rtc_time passed to mach_hwclk() is
zero-based, and atari_mste_hwclk(), atari_tt_hwclk(), bvme6000_hwclk(),
mac_hwclk() and q40_hwclk() all make this adjustment. Unfortunately,
dn_dummy_hwclk(), mvme147_hwclk(), mvme16x_hwclk(), sun3_hwclk() and
sun3x_hwclk() fail to decrement tm_mon. Also m68328_hwclk() assumes
a one-based tm_mon.
Bring these platforms into line and fix read_persistent_clock() so it
works correctly on all m68k platforms.
The datasheets for the RTC devices found on the affected platforms
all confirm that the year is stored as a value in the range 0-99 and
the month is stored as a value in the range 1-12. Please refer to the
datasheets for MC146818 (Apollo), DS1643 (MVME), ICM7170 (Sun 3)
and M48T02 (Sun 3x).
Reported-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/apollo')
| -rw-r--r-- | arch/m68k/apollo/config.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/m68k/apollo/config.c b/arch/m68k/apollo/config.c index 0d27706f14d4..b2a6bc63f8cd 100644 --- a/arch/m68k/apollo/config.c +++ b/arch/m68k/apollo/config.c @@ -221,8 +221,10 @@ int dn_dummy_hwclk(int op, struct rtc_time *t) { t->tm_hour=rtc->hours; t->tm_mday=rtc->day_of_month; t->tm_wday=rtc->day_of_week; - t->tm_mon=rtc->month; + t->tm_mon = rtc->month - 1; t->tm_year=rtc->year; + if (t->tm_year < 70) + t->tm_year += 100; } else { rtc->second=t->tm_sec; rtc->minute=t->tm_min; @@ -230,8 +232,8 @@ int dn_dummy_hwclk(int op, struct rtc_time *t) { rtc->day_of_month=t->tm_mday; if(t->tm_wday!=-1) rtc->day_of_week=t->tm_wday; - rtc->month=t->tm_mon; - rtc->year=t->tm_year; + rtc->month = t->tm_mon + 1; + rtc->year = t->tm_year % 100; } return 0; |