mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: "Alexander Shiyan" <shc_work@mail.ru>
To: "Sascha Hauer" <s.hauer@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [JUST RFC] ARM: DIGIC: add csrc-dummy
Date: Mon, 16 Dec 2013 11:48:52 +0400	[thread overview]
Message-ID: <1387180132.313029323@f309.i.mail.ru> (raw)
In-Reply-To: <20131216074158.GP24559@pengutronix.de>

> On Sun, Dec 15, 2013 at 07:02:05PM +0400, Antony Pavlov wrote:
> > The clocksource csrc-timer driver that uses DIGIC
> > hardware TIMER2 perfectrly works on Canon A1100,
> > but does not works on Canon EOS 600D.
> > IMHO we need additional timer initialisation.
> > 
> > This patch introduces a quick-and-dirty termporary
> > solution for this situation: a clocksource driver that
> > does not use any hardware at all.
> > 
> > Also this driver is very handy for running barebox
> > on Magic Lantern EOS qemu-based emulator as
> > the emulator does not realize timer counter register at all!
...
> I also played with the same approach. In my case it was more a fallback
> when the initialization order was wrong so that the time functions were
> used before the real clocksource was initialized. Without it time never
> advanced and every udelay() locked up the system (or it crashed because
> we didn't check for the clocksource being NULL, can't remember).
> 
> Maybe it would be possible to add this clocksource unconditionally on
> every build, but let a real clocksource take over.
> 
> To do this and not silently fall back to a dummy console I suggest a:
> 
> static uint64_t dummy_cs_read(void)
> {
> 	static int first;
> 
> 	if (!first) {
> 		pr_warn("Warning: Using dummy clocksource\n");
> 		first = 0;

first =1;

---
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

      parent reply	other threads:[~2013-12-16  7:49 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-15 15:02 [JUST RFC] add hardware independent clock source Antony Pavlov
2013-12-15 15:02 ` [JUST RFC] ARM: DIGIC: add csrc-dummy Antony Pavlov
2013-12-15 18:08   ` Alexander Shiyan
2013-12-15 18:52     ` Antony Pavlov
2013-12-15 18:50       ` Alexander Shiyan
2013-12-15 19:30   ` Alexander Aring
2013-12-15 20:40     ` Antony Pavlov
2013-12-15 21:17       ` Alexander Aring
2013-12-16  7:41   ` Sascha Hauer
2013-12-16  7:46     ` Alexander Aring
2013-12-16  7:48     ` Alexander Shiyan [this message]

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=1387180132.313029323@f309.i.mail.ru \
    --to=shc_work@mail.ru \
    --cc=barebox@lists.infradead.org \
    --cc=s.hauer@pengutronix.de \
    /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