From: Robin Murphy <robin.murphy@arm.com>
To: Johan Jonker <jbx6244@gmail.com>, heiko@sntech.de
Cc: robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, paweljarosz3691@gmail.com
Subject: Re: [PATCH] ARM: dts: rockchip: remove cap-mmc-highspeed property from mk808 &mmc0 node
Date: Fri, 20 Aug 2021 15:49:10 +0100 [thread overview]
Message-ID: <d3b574f5-b49e-60be-1559-b98e0832bd62@arm.com> (raw)
In-Reply-To: <c52b4cf0-d018-f6b4-8728-41551b8bf62b@gmail.com>
On 2021-08-20 15:41, Johan Jonker wrote:
>
>
> On 8/20/21 4:17 PM, Robin Murphy wrote:
>> On 2021-08-20 14:19, Johan Jonker wrote:
>>> On the MK808 only a microSD slot is connected with the SDMMC Host
>>> Controller,
>>> so remove the cap-mmc-highspeed property from the &mmc0 node.
>>
>> Why, does it do any harm?
>
> Harm not. Example rk3066 u-boot:
>
>>>>> sd_select_mode_and_width
> sd card: widths [4, 1, \b\b] modes [MMC legacy, SD High Speed (50MHz), UHS
> SDR12 (25MHz), UHS SDR25 (50MHz), \b\b]
> host: widths [4, 1, \b\b] modes [MMC legacy, MMC High Speed (26MHz), SD
> High Speed (50MHz), MMC High Speed (52MHz), \b\b]
> trying mode SD High Speed (50MHz) width 4 (at 50 MHz)
>
> I would say only advertise host capabilities that are under normal
> circumstances occur. How realistic is it to use a TF/Micro SD TO SD Card
> Extension Cable Adapter (giggle) for a deprecated mmc card?
Well, if you want a far more realistic example:
https://www.hardkernel.com/shop/emmc-module-reader-board-for-os-upgrade/
Who are we to dictate what "normal circumstances" are, and what do we
gain by removing support for modes that could work fine and at least be
useful to someone on occasion?
Robin.
prev parent reply other threads:[~2021-08-20 14:49 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 13:19 [PATCH] ARM: dts: rockchip: remove cap-mmc-highspeed property from mk808 &mmc0 node Johan Jonker
2021-08-20 14:17 ` Robin Murphy
2021-08-20 14:41 ` Johan Jonker
2021-08-20 14:49 ` Robin Murphy [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=d3b574f5-b49e-60be-1559-b98e0832bd62@arm.com \
--to=robin.murphy@arm.com \
--cc=devicetree@vger.kernel.org \
--cc=heiko@sntech.de \
--cc=jbx6244@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
--cc=paweljarosz3691@gmail.com \
--cc=robh+dt@kernel.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).