From: Linus Walleij <linus.walleij@linaro.org>
To: "Alejandro González" <alejandro.gonzalez.correo@gmail.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
Maxime Ripard <maxime.ripard@bootlin.com>,
Greg KH <gregkh@linuxfoundation.org>,
linux-sunxi <linux-sunxi@googlegroups.com>,
linux-mmc <linux-mmc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Chen-Yu Tsai <wens@csie.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] mmc: sunxi: fix unusuable eMMC on some H6 boards by disabling DDR
Date: Wed, 28 Aug 2019 14:52:30 +0200 [thread overview]
Message-ID: <CACRpkdazfe3gJr6Q+X05GzxPuKtUg0M780SPA_oR5bd+-xBPvA@mail.gmail.com> (raw)
In-Reply-To: <20190825150558.15173-1-alejandro.gonzalez.correo@gmail.com>
On Sun, Aug 25, 2019 at 5:06 PM Alejandro González
<alejandro.gonzalez.correo@gmail.com> wrote:
> Jernej Skrabec compared the BSP driver with this
> driver, and found that the BSP driver configures pinctrl to operate at
> 1.8 V when entering DDR mode (although 3.3 V operation is supported), while
> the mainline kernel lacks any mechanism to switch voltages dynamically.
(...)
> the kernel lacks the required
> dynamic pinctrl control for now
This is not a pin control thing, the I/O voltage level is usually
controlled by a regulator called VCCQ, if the selection of the
voltage rails is inside the pin control registers, see the solution
in drivers/pinctrl/sh-pfc/pfc-sh73a0.c where we simply provide
a regulator from inside the pinctrl driver to make things easy
for the MMC core. Do this thing!
If you don't have time to fix it up properly right now I would slap
in a big FIXME in the code so people know this needs
to be fixed properly.
Yours,
Linus Walleij
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-08-28 12:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-25 15:05 [PATCH] mmc: sunxi: fix unusuable eMMC on some H6 boards by disabling DDR Alejandro González
2019-08-27 13:24 ` Ulf Hansson
2019-08-28 10:52 ` Alejandro González
2019-08-29 11:37 ` Ulf Hansson
2019-08-27 13:32 ` Maxime Ripard
2019-08-28 12:52 ` Linus Walleij [this message]
2019-08-28 13:29 ` [linux-sunxi] " Chen-Yu Tsai
2019-08-28 13:43 ` Maxime Ripard
2019-08-28 13:46 ` Chen-Yu Tsai
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=CACRpkdazfe3gJr6Q+X05GzxPuKtUg0M780SPA_oR5bd+-xBPvA@mail.gmail.com \
--to=linus.walleij@linaro.org \
--cc=alejandro.gonzalez.correo@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux-sunxi@googlegroups.com \
--cc=maxime.ripard@bootlin.com \
--cc=tglx@linutronix.de \
--cc=ulf.hansson@linaro.org \
--cc=wens@csie.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).