| Message ID | 20180324192455.12254-8-mdavidsaver@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Generalize Dallas/Maxim I2C RTC devices v2 | expand |
On 24 March 2018 at 19:24, Michael Davidsaver <mdavidsaver@gmail.com> wrote: > Correctly handle different real weekday in > guest and host timezones. > Allow guest to use any day as start of week > (day 1). eg. Monday instead of Sunday. > > Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com> > --- > hw/timer/ds1338.c | 24 ++++++++++++++++-------- > 1 file changed, 16 insertions(+), 8 deletions(-) > > diff --git a/hw/timer/ds1338.c b/hw/timer/ds1338.c > index 071c031563..a969b5c8ba 100644 > --- a/hw/timer/ds1338.c > +++ b/hw/timer/ds1338.c > @@ -108,7 +108,10 @@ static void capture_current_time(DS1338State *s) > } else { > ARRAY_FIELD_DP32(s->nvram, HOUR, HOUR24, to_bcd(now.tm_hour)); > } > - s->nvram[R_WDAY] = (now.tm_wday + s->wday_offset) % 7 + 1; > + s->nvram[R_WDAY] = (now.tm_wday + s->wday_offset) % 7; > + if (s->nvram[R_WDAY] == 0) { > + s->nvram[R_WDAY] = 7; > + } > s->nvram[R_DATE] = to_bcd(now.tm_mday); > s->nvram[R_MONTH] = to_bcd(now.tm_mon + 1); > s->nvram[R_YEAR] = to_bcd(now.tm_year - 100); > @@ -182,17 +185,22 @@ static void ds1338_update(DS1338State *s) > } else { > now.tm_hour = from_bcd(ARRAY_FIELD_EX32(s->nvram, HOUR, HOUR24)); > } > - { > - /* The day field is supposed to contain a value in > - the range 1-7. Otherwise behavior is undefined. > - */ > - int user_wday = (s->nvram[R_WDAY] & 7) - 1; > - s->wday_offset = (user_wday - now.tm_wday + 7) % 7; > - } > + now.tm_wday = from_bcd(s->nvram[R_WDAY]) - 1u; > now.tm_mday = from_bcd(s->nvram[R_DATE] & 0x3f); You don't need to set now.tm_wday -- qemu_timedate_diff() will not use that field in the structure you hand it. > now.tm_mon = from_bcd(s->nvram[R_MONTH] & 0x1f) - 1; > now.tm_year = from_bcd(s->nvram[R_YEAR]) + 100; > s->offset = qemu_timedate_diff(&now); > + > + { > + /* Round trip to get real wday_offset based on time delta and > + * ref. timezone. > + * Race if midnight (in ref. timezone) happens here. > + */ > + int user_wday = now.tm_wday; > + qemu_get_timedate(&now, s->offset); > + > + s->wday_offset = (user_wday - now.tm_wday) % 7 + 1; > + } > } Ah, this part is fixing the bug I pointed out in the earlier patch. You should just fold that bug fix into it. thanks -- PMM
diff --git a/hw/timer/ds1338.c b/hw/timer/ds1338.c index 071c031563..a969b5c8ba 100644 --- a/hw/timer/ds1338.c +++ b/hw/timer/ds1338.c @@ -108,7 +108,10 @@ static void capture_current_time(DS1338State *s) } else { ARRAY_FIELD_DP32(s->nvram, HOUR, HOUR24, to_bcd(now.tm_hour)); } - s->nvram[R_WDAY] = (now.tm_wday + s->wday_offset) % 7 + 1; + s->nvram[R_WDAY] = (now.tm_wday + s->wday_offset) % 7; + if (s->nvram[R_WDAY] == 0) { + s->nvram[R_WDAY] = 7; + } s->nvram[R_DATE] = to_bcd(now.tm_mday); s->nvram[R_MONTH] = to_bcd(now.tm_mon + 1); s->nvram[R_YEAR] = to_bcd(now.tm_year - 100); @@ -182,17 +185,22 @@ static void ds1338_update(DS1338State *s) } else { now.tm_hour = from_bcd(ARRAY_FIELD_EX32(s->nvram, HOUR, HOUR24)); } - { - /* The day field is supposed to contain a value in - the range 1-7. Otherwise behavior is undefined. - */ - int user_wday = (s->nvram[R_WDAY] & 7) - 1; - s->wday_offset = (user_wday - now.tm_wday + 7) % 7; - } + now.tm_wday = from_bcd(s->nvram[R_WDAY]) - 1u; now.tm_mday = from_bcd(s->nvram[R_DATE] & 0x3f); now.tm_mon = from_bcd(s->nvram[R_MONTH] & 0x1f) - 1; now.tm_year = from_bcd(s->nvram[R_YEAR]) + 100; s->offset = qemu_timedate_diff(&now); + + { + /* Round trip to get real wday_offset based on time delta and + * ref. timezone. + * Race if midnight (in ref. timezone) happens here. + */ + int user_wday = now.tm_wday; + qemu_get_timedate(&now, s->offset); + + s->wday_offset = (user_wday - now.tm_wday) % 7 + 1; + } } static int ds1338_send(I2CSlave *i2c, uint8_t data)
Correctly handle different real weekday in guest and host timezones. Allow guest to use any day as start of week (day 1). eg. Monday instead of Sunday. Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com> --- hw/timer/ds1338.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)