public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: tony@atomide•com (Tony Lindgren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/2] mfd: twl6040: Fix deferred probe handling for clk32k
Date: Mon, 21 Sep 2015 06:59:56 -0700	[thread overview]
Message-ID: <20150921135956.GB23801@atomide.com> (raw)
In-Reply-To: <55FFD422.2080506@ti.com>

* Peter Ujfalusi <peter.ujfalusi@ti•com> [150921 02:59]:
> On 09/18/2015 07:29 PM, Tony Lindgren wrote:
> > Commit 68bab8662f49 ("mfd: twl6040: Optional clk32k clock handling")
> > added clock handling for the 32k clock from palmas-clk. However, that
> > patch did not consider a typical situation where twl6040 is built-in,
> > and palmas-clk is a loadable module like we have in omap2plus_defconfig.
> > 
> > If palmas-clk is not loaded before twl6040 probes, we will get a
> > "clk32k is not handled" warning during booting. This means that any
> > drivers relying on this clock will mysteriously fail, including
> > omap5-uevm WLAN and audio.
> > 
> > Note that for WLAN, we probably should also eventually get
> > the clk32kgaudio for MMC3 directly as that's shared between
> > audio and WLAN SDIO at least for omap5-uevm. It seems the
> > WLAN chip cannot get it as otherwise MMC3 won't get properly
> > probed.
> 
> While this is going to 'fix' the WLAN because currently the twl6040 is powered
> on all the time (32k clock is enabled). My plan is to finally implement the
> power state handling for the twl6040, which means that w/o audio activity the
> twl6040 will be turned off. This will imply that any clock which is only used
> by twl6040 will be off as well.
> The proper solution would be to add clock handling to the WLAN driver stack.

Yes the place to request this clock is using pwrseq_simple.c for MMC3.
It seems there are some issues with deferred probe handling there too
though.

Regards,

Tony

  reply	other threads:[~2015-09-21 13:59 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-18 16:29 [PATCH 0/2] Fix omap5-uevm WLAN regressions Tony Lindgren
2015-09-18 16:29 ` [PATCH 1/2] mfd: twl6040: Fix deferred probe handling for clk32k Tony Lindgren
2015-09-18 16:40   ` Felipe Balbi
2015-09-19  9:57   ` Lee Jones
2015-09-21  9:55   ` Peter Ujfalusi
2015-09-21 13:59     ` Tony Lindgren [this message]
2015-09-18 16:29 ` [PATCH 2/2] ARM: dts: Fix WLAN regression on omap5-uevm Tony Lindgren
2015-09-18 16:40   ` Robert Nelson
2015-09-18 16:51     ` Tony Lindgren
2015-09-18 17:22       ` Tony Lindgren
2015-09-18 18:39       ` Robert Nelson
2015-09-19 21:12         ` Grazvydas Ignotas
2015-09-19 22:52           ` Tony Lindgren
2015-09-18 17:35   ` Javier Martinez Canillas
2015-09-18 17:48     ` Tony Lindgren
2015-09-18 20:27       ` Tony Lindgren
2015-09-18 20:35         ` Tony Lindgren
2015-09-21  9:13         ` Javier Martinez Canillas
2015-09-21 14:10           ` Tony Lindgren
2015-09-23 21:06             ` Tony Lindgren

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=20150921135956.GB23801@atomide.com \
    --to=tony@atomide$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

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