Hi Alex -
--- In Alexander Clouter <> wrote:
>
> Hi,
>
> jirimacku <> [20080311 16:45:34 -0000]:
> >
> > --- In "Michael" <michael@> wrote:
> > >
> > > > The time obtained from RTC by rtc7800 makes random jumps. To
find out
> > > > more details I added following to crontab:
> >
> >
> I would be interested in your results for *after* the jump too, as
well as at
> (5+10x) minutely intervals. Does it give you a sane value or is the
huge
Good question, I thought of that too.
> offset maintained? Problem is I vaguely recall the utility does not
support
> "just give me the time that the RTC thinks it is", you *have* to set
the time
> too :-/
Yes, it needs a -r switch that just reads & dumps the registers.
>
> More so strange is that the mainline 2.6.24 rtc-m48t86.c driver does
not do
> this locking...maybe just an oversight as how likely are you going
to boot
> your machine and it enters the 'm48t86_rtc_read_time' fuction just
as the
> clock rolls over to 0:00:00.
You're right, the m48tc86 doesn't lock around the read_time fn, but it
does around the set_time fn.
>
> > > Can you download and install this program to your board (should
overwrite
> > > the existing copy in /usr/local/bin/rtc7800) and let me know if
it fixes
> > > the problem?
> >
> > [snipped]
> >
> > I've compiled the patched source (thanks Charlie!) and will report the
> > result tomorrow.
> >
> The rtc7800.c file I have (downloaded on the 4th March) already has
this
> locking code....
I don't think it does, at least not what I saw today. I just added
another set of disable update & enable update around the register
reads; maybe you saw the existing code around the writes.
It's really just a WAG (wild ass guess) from reading the datasheet.
But looking at the register layout and expected data, it looks like
something else is going on.
Are you sure there is no kernel module claiming the RTC in the TS
distro? Accessing the same device from the kernel and userland is
looking for trouble.
Regards, ..... Charlie
>
> :/usr/src/ts7800$ md5sum rtc7800.c
> 6f81e9b8568aeababd889f0ebfc1a61e rtc7800.c
>
> The plot thickens...
>
> Cheers
>
> Alex
>
> --
> _________________________________
> / One good turn deserves another. \
> | |
> \ -- Gaius Petronius /
> ---------------------------------
> \ ^__^
> \ (oo)\_______
> (__)\ )\/\
> ||----w |
> || ||
>
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ts-7000/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/ts-7000/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|