From: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
To: Doug Anderson <dianders@chromium.org>,
Jaehoon Chung <jh80.chung@samsung.com>,
Seungwon Jeon <tgih.jun@samsung.com>,
Ulf Hansson <ulf.hansson@linaro.org>
Cc: Alim Akhtar <alim.akhtar@samsung.com>,
Sonny Rao <sonnyrao@chromium.org>,
Andrew Bresticker <abrestic@chromium.org>,
Heiko Stuebner <heiko@sntech.de>,
Addy Ke <addy.ke@rock-chips.com>,
Alexandru Stan <amstan@chromium.org>,
chris@printf.net, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mmc: dw_mmc: Don't start commands while busy
Date: Wed, 25 Feb 2015 19:22:39 +0100 [thread overview]
Message-ID: <54EE12EF.20607@collabora.co.uk> (raw)
In-Reply-To: <1424464316-4397-1-git-send-email-dianders@chromium.org>
Hello Doug,
On 02/20/2015 09:31 PM, Doug Anderson wrote:
> We've seen problems on some WiFi modules where we seem to send a CMD53
> (which requires the data lines) while the module is asserting busy.
> We shouldn't do that.
>
> The Designware Databook says that before issuing a new data transfer
> command we should check for busy, so that's what we'll do.
>
> We'll leverage the existing dw_mmc knowledge about whether it should
> wait for the previous command to finish to know whether we should
> check for busy before sending the command. This means we won't end up
> incorrectly waiting for things like CMD52 (SDIO) or CMD13 (SD) which
> don't use the data line.
>
> Note that this also has the advantage of making sure that we don't
> change the clock while the card is busy, too.
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
>
On an Exynos5250 Snow, Exynos5420 Peach Pit and Exynos5800 Peach Pi:
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Best regards,
Javier
prev parent reply other threads:[~2015-02-25 18:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-20 20:31 [PATCH v2] mmc: dw_mmc: Don't start commands while busy Doug Anderson
2015-02-21 3:33 ` addy ke
2015-02-23 16:33 ` Javier Martinez Canillas
2015-02-23 19:45 ` Doug Anderson
2015-02-24 11:20 ` Javier Martinez Canillas
2015-02-25 5:43 ` Doug Anderson
2015-02-25 10:02 ` Javier Martinez Canillas
2015-02-25 18:22 ` Javier Martinez Canillas [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=54EE12EF.20607@collabora.co.uk \
--to=javier.martinez@collabora.co.uk \
--cc=abrestic@chromium.org \
--cc=addy.ke@rock-chips.com \
--cc=alim.akhtar@samsung.com \
--cc=amstan@chromium.org \
--cc=chris@printf.net \
--cc=dianders@chromium.org \
--cc=heiko@sntech.de \
--cc=jh80.chung@samsung.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=sonnyrao@chromium.org \
--cc=tgih.jun@samsung.com \
--cc=ulf.hansson@linaro.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.