linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Eugene Surovegin <ebs@ebshome.net>
To: Dan Malek <dan@embeddededge.com>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [RFC] Option to disable mapping genrtc calls to ppc_md calls
Date: Tue, 18 Jan 2005 10:54:19 -0800	[thread overview]
Message-ID: <20050118185418.GA31308@gate.ebshome.net> (raw)
In-Reply-To: <93780AB0-696D-11D9-81BE-003065F9B7DC@embeddededge.com>

On Tue, Jan 18, 2005 at 11:25:33AM -0500, Dan Malek wrote:
> There are three reasons.  You don't want to use an I2c rtc clock at
> all in these functions because they get can get called from the
> clock interrupt to update the time in the rtc.  If it does happen to 
> work,
> it creates long latencies in the timer interrupt.  If the i2c requires 
> an
> interrupt, they system will crash or hang.
> 
> A system using an I2C RTC should find some way to access the
> clock from application space as a standard I2C device and manage
> time/clock from the application, not from the kernel.

Well, it was discussed numerous times before with solutions how to use 
i2c based RTC as well.

I use i2c RTC which requires interrupt and guess what, my kernel 
doesn't crash when timer_interrupt calls ppc_md.set_rtc_time.

It's just a matter of writing correct i2c RTC driver.

Dan, please, stop spreading "i2c-RTC" FUD :).

--
Eugene

  parent reply	other threads:[~2005-01-18 19:01 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-01-17 21:10 [RFC] Option to disable mapping genrtc calls to ppc_md calls Mark A. Greer
2005-01-18  9:20 ` Geert Uytterhoeven
2005-01-18 18:40   ` Mark A. Greer
2005-01-18 19:01     ` Eugene Surovegin
2005-01-18 16:15 ` Tom Rini
2005-01-18 16:25   ` Dan Malek
2005-01-18 17:39     ` Tolunay Orkun
2005-01-18 18:33       ` Tom Rini
2005-01-18 18:13     ` Tom Rini
2005-01-18 18:58       ` Mark A. Greer
2005-01-18 19:08         ` Tom Rini
2005-01-18 19:43           ` Mark A. Greer
2005-01-19 18:08             ` Tom Rini
2005-01-20 20:52               ` Mark A. Greer
2005-01-20 22:53                 ` Tom Rini
2005-01-20 23:21                   ` Mark A. Greer
2005-01-20 23:47                     ` Tom Rini
2005-01-20 23:56                       ` Mark A. Greer
2005-01-18 18:54     ` Eugene Surovegin [this message]
2005-01-20 22:27     ` Benjamin Herrenschmidt
2005-01-18 18:55   ` Mark A. Greer
2005-01-18 19:05     ` Tom Rini
2005-01-18 19:33       ` Mark A. Greer
2005-01-20 22:25 ` Benjamin Herrenschmidt
2005-01-20 23:54   ` Mark A. Greer
2005-01-21  0:01     ` Benjamin Herrenschmidt
2005-01-21  0:09       ` Mark A. Greer
2005-01-21  0:12         ` Benjamin Herrenschmidt
2005-01-21  9:14           ` Geert Uytterhoeven
2005-01-21 14:39             ` Corey Minyard
2005-01-21 22:01             ` Benjamin Herrenschmidt
2005-01-21  9:44         ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20050118185418.GA31308@gate.ebshome.net \
    --to=ebs@ebshome.net \
    --cc=dan@embeddededge.com \
    --cc=linuxppc-dev@ozlabs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).