linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: jamesjj.liao@mediatek.com (James Liao)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/4] soc: mediatek: Init MT8173 scpsys driver earlier
Date: Thu, 31 Dec 2015 13:59:26 +0800	[thread overview]
Message-ID: <1451541566.10610.10.camel@mtksdaap41> (raw)
In-Reply-To: <6145950.8rtkDup7QD@wuerfel>

Hi Arnd,

On Wed, 2015-12-30 at 11:35 +0100, Arnd Bergmann wrote:
> On Wednesday 30 December 2015 18:12:08 James Liao wrote:
> > On Wed, 2015-12-30 at 09:52 +0100, Arnd Bergmann wrote:
> > > On Wednesday 30 December 2015 14:41:44 James Liao wrote:
> > > > Some power domain comsumers may init before module_init.
> > > > So the power domain provider (scpsys) need to be initialized
> > > > earlier too.
> > > > 
> > > > Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
> > > > ---
> > > > 
> > > 
> > > Why?
> > 
> > Some drivers use different init level to ensure they can be initialized
> > before other drivers. To support these drivers, moving scpsys driver's
> > initial function to subsys_init is the most easy way.
> 
> This is just the same generic explanation that you already have.
> 
> Please be more specific what the dependency is and why we can't rely
> on deferred probing here.

In our case, there is a SMI driver provide APIs to control multiple
devices that attached to different power domains.Video encoder / decoder
and GPU drivers are SMI users. It's not easy for SMI users to detect SMI
and scpsys driver are initialized or not. A most easy way to resolve the
init sequence issue is moving SMI and scpsys driver in early init stage.

Do you prefer to keep scpsys driver's init in module_init? If yes, I can
remove this patch in next version.


Best regards,

James

  reply	other threads:[~2015-12-31  5:59 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-30  6:41 [PATCH 0/4] Mediatek MT2701 SCPSYS power domain support James Liao
2015-12-30  6:41 ` [PATCH 1/4] soc: mediatek: Separate scpsys driver common code James Liao
2015-12-30  8:52   ` Arnd Bergmann
2015-12-30 10:08     ` James Liao
2015-12-30  6:41 ` [PATCH 2/4] soc: mediatek: Init MT8173 scpsys driver earlier James Liao
2015-12-30  8:52   ` Arnd Bergmann
2015-12-30 10:12     ` James Liao
2015-12-30 10:35       ` Arnd Bergmann
2015-12-31  5:59         ` James Liao [this message]
2015-12-31  9:16           ` James Liao
2015-12-31 14:45             ` Arnd Bergmann
2016-01-04  2:52               ` James Liao
2015-12-30  6:41 ` [PATCH 3/4] soc: mediatek: Add MT2701 power dt-bindings James Liao
2015-12-30  6:41 ` [PATCH 4/4] soc: mediatek: Add MT2701/MT7623 scpsys driver James Liao
2015-12-30  9:01   ` Daniel Kurtz
2015-12-30 10:18     ` James Liao
2015-12-30 17:49       ` Matthias Brugger
2016-01-05  5:23         ` James Liao
2016-01-08 11:26           ` Matthias Brugger

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=1451541566.10610.10.camel@mtksdaap41 \
    --to=jamesjj.liao@mediatek.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;
as well as URLs for NNTP newsgroup(s).