Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 18 Oct 2002 05:06:24 +1000 (EST)
From:      Bruce Evans <bde@zeta.org.au>
To:        Mitsuru IWASAKI <iwasaki@FreeBSD.org>
Cc:        cvs-committers@FreeBSD.org, <cvs-all@FreeBSD.org>
Subject:   Re: cvs commit: src/sys/i386/isa clock.c
Message-ID:  <20021018050254.U12092-100000@gamplex.bde.org>
In-Reply-To: <200210171355.g9HDtjBt054703@repoman.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 17 Oct 2002, Mitsuru IWASAKI wrote:

> iwasaki     2002/10/17 06:55:44 PDT
>
>   Modified files:
>     sys/i386/isa         clock.c
>   Log:
>   1. Fix a comment.  Locking _is_ needed (but not done).
>   2. Update a comment.  We now restore much more than RTC updates and
>      interrupts.
>   3. Order change.  Stop interrupts by writing to RTC_STATUSB,
>      ...
>   4. Don't stop the clock (RTCB_HALT).  We only program some control bits
>      and don't want to stop the clock.
>   5. (Not really related.)  Add caveats to the comment about timer_restore().
>      The update is non-atomic since locking is not done.
>
>   On locking:
>   6. rtcin() and writertc() are locked() adequately by splhigh() in RELENG_4,
>      but this locking is null in -current.
>   7. Doing things in the correct order in (3) combined with (6) is probably
>      enough locking for rtcrestore() in RELENG_4.  In -current, the
>      writertc()'s race with rtcintr() unless the BIOS disables RTC interrupts.
>
>   Submitted by:   bde (including commit message)
>   MFC after:      1 week

Thanks.

The commit message is a bit too verbose.  Please summarize it and adjust
the comments for the MFC (most of the locking problems are only in
-current).

Bruce


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20021018050254.U12092-100000>