linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Luciano Coelho <luciano.coelho@nokia.com>
To: ext Ohad Ben-Cohen <ohad@wizery.com>, Chris Ball <cjb@laptop.org>
Cc: "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	Nicolas Pitre <nico@fluxnic.net>
Subject: Re: [PATCH v2 00/11] SDIO Runtime PM Support
Date: Thu, 07 Oct 2010 15:32:16 +0300	[thread overview]
Message-ID: <1286454736.27371.37.camel@chilepepper> (raw)
In-Reply-To: <1286020455-28946-1-git-send-email-ohad@wizery.com>

On Sat, 2010-10-02 at 13:54 +0200, ext Ohad Ben-Cohen wrote:
> Introduce SDIO runtime PM support:
> 
> 1. Power to SDIO cards is kept low until one of its functions is bound
>    (i.e. a matching driver is successfully probed)
> 
> 2. If the matching driver supports runtime PM, power to the card is
>    dropped soon after probe() returns. It is then up to the driver
>    to request power to its function, using runtime PM API (the get/put
>    variants). This is demonstrated with the wl1271 driver, in which
>    the power of the card power is coupled with the state of the wlan
>    interface (interface up -> power is up, interface down -> power is down)
> 
> 3. If a matching driver does not support runtime PM, power to the card
>    is kept high during the whole lifetime of the driver
> 
> 4. When the driver is removed, power to the card is immediately dropped
> 
> 5. If there are multiple drivers for the same card (several SDIO functions),
>    power will be pulled high before the first driver probes, and dropped
>    down after the last driver is removed. In between, power will be
>    maintained accrording to the accumulated usage count of the complete
>    drivers group
> 
> 6. SDIO suspend/resume semantics are unchanged. In addition, when the system
>    comes out of suspend, it is guaranteed that the power state of the
>    SDIO card will reflect its runtime PM usage count.
> 
> 7. What was NOT changed:
>    - Interface: drivers can still assume that the card is powered
>      when probe/remove/suspend/resume are called
>    - Existing behavior: drivers that do not support runtime PM
>      are unchanged
> 
> Changes since v1:
> - Interaction with system suspend/resume
> - Better commentary
> 
> Dependencies:
> - SDIO patches are against mmc-next, and have a runtime dependency on
>   commit "PM / Runtime: Lenient generic runtime pm callbacks"
>   (patch is in linux-next now)
> - WLAN patches depend on recent wl1271 activity, and they are here
>   just to demonstrate the usage of the SDIO patchset (will be
>   resubmitted separately)
> 
> The full patchset, together with all its dependencies, is also available at:
> git://wizery.com/pub/mmc.git runtime-pm-v2

I have tested this on my beagle board with the wl1271 patches that Ohad
provided and it seems to be working fine.  I've also created a small
script to stress test the implementation a little bit and didn't see any
problems.

Tested-by: Luciano Coelho <luciano.coelho@nokia.com>

This is quite an important fix in the wl1271 point-of-view.  Chris, do
you think there is any chance that this could make it to 2.6.37?


-- 
Cheers,
Luca.


  parent reply	other threads:[~2010-10-07 12:32 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-02 11:54 [PATCH v2 00/11] SDIO Runtime PM Support Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 01/11] mmc: sdio: fully reconfigure oldcard on resume Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 02/11] mmc: propagate power save/restore ops return value Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 03/11] sdio: add power_restore support Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 04/11] mmc: add runtime PM handlers Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 05/11] sdio: use the generic " Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 06/11] sdio: enable runtime PM for SDIO cards Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 07/11] sdio: enable runtime PM for SDIO functions Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 08/11] sdio: ensure mmc_sdio_detect is powered Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 09/11] sdio: support suspend/resume while runtime suspended Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 10/11] wl1271: sdio: enable runtime PM Ohad Ben-Cohen
2010-10-02 11:54 ` [PATCH v2 11/11] wl1271: sdio: add suspend/resume support Ohad Ben-Cohen
2010-10-07 12:32 ` Luciano Coelho [this message]
2010-10-07 18:01   ` [PATCH v2 00/11] SDIO Runtime PM Support Chris Ball
2010-10-07 18:33     ` Ohad Ben-Cohen
2010-10-08  5:00     ` Luciano Coelho

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=1286454736.27371.37.camel@chilepepper \
    --to=luciano.coelho@nokia.com \
    --cc=cjb@laptop.org \
    --cc=linux-mmc@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=nico@fluxnic.net \
    --cc=ohad@wizery.com \
    /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).