public inbox for linux-arm-kernel@lists.infradead.org
 help / color / mirror / Atom feed
From: maxime.ripard@free-electrons.com (Maxime Ripard)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] clk: sunxi: Accept a greater rate when setting a parent clock
Date: Thu, 14 Apr 2016 21:31:32 +0200	[thread overview]
Message-ID: <20160414193132.GT4005@lukather> (raw)
In-Reply-To: <20160414201428.0c89d3b943db543c3ab08740@free.fr>

Hi,

On Thu, Apr 14, 2016 at 08:14:28PM +0200, Jean-Francois Moine wrote:
> On Thu, 14 Apr 2016 19:24:00 +0200
> Maxime Ripard <maxime.ripard@free-electrons.com> wrote:
> 
> > > >> That being said, we had a similar discussion for SPI around a month
> > > >> ago where we wanted a rate strictly lower than the requested one. I
> > > >> guess it's time to add a flag to tell how you want to round.
> > > > 
> > > > You are right, I just removed half of the constraint, but I still wonder
> > > > why does this sequence introduced by the commit 862b728387aef3a37
> > > > (clk: sunxi: factors: automatic reparenting support) do
> > > > 	"provide the fastest rate <= rate"
> > > > instead of
> > > > 	"provide the closest rate" ?
> > > > 
> > > > Emilio?
> > > 
> > > Overclocking components is usually not a good default in my opinion. I
> > > don't recall at the moment if there was some other justification apart
> > > from playing it safe.
> > 
> > Yeah, I'd agree, it should be the exception rather than the norm. In
> > some cases that are very timings sensitive (audio or video), we
> > probably want to enforce something as close as possible to the
> > expected rate, even if it trips above the rate.
> > 
> > For all the other, I'd prefer to keep the current behaviour.
> 
> OK, then, as I have no solution for this clock, there will be no audio
> 44.1KHz from the H3...

You have not read me. I already suggested in the quote above to add a
flag to tell how we should round the clock rate, the default remaining
to round it down.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20160414/524b3ef2/attachment.sig>

  reply	other threads:[~2016-04-14 19:31 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20160310081658.B749246B@mail.free-electrons.com>
2016-03-21  7:25 ` [PATCH] clk: sunxi: Accept a greater rate when setting a parent clock Maxime Ripard
2016-03-21  8:25   ` Jean-Francois Moine
2016-03-29  9:38     ` Maxime Ripard
2016-03-29 10:08       ` Jean-Francois Moine
2016-03-30 20:49     ` Emilio López
2016-04-14 17:24       ` Maxime Ripard
2016-04-14 18:14         ` Jean-Francois Moine
2016-04-14 19:31           ` Maxime Ripard [this message]
     [not found] <E1advmk-0004Nt-Ba@bombadil.infradead.org>
2016-03-18  7:47 ` Jean-Francois Moine
2016-03-10  7:15 Jean-Francois Moine

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=20160414193132.GT4005@lukather \
    --to=maxime.ripard@free-electrons.com \
    --cc=linux-arm-kernel@lists.infradead.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