From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: Detlev Casanova <detlev.casanova@collabora.com>,
Shawn Guo <shawnguo@kernel.org>
Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Sascha Hauer <s.hauer@pengutronix.de>,
linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
NXP Linux Team <linux-imx@nxp.com>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Fabio Estevam <festevam@gmail.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] ARM: dts: imx6qdl-sabre: Add mmc aliases
Date: Mon, 28 Nov 2022 09:42:59 +0100 [thread overview]
Message-ID: <a13c2e92-cfa6-04fd-c32a-c4d444894660@pengutronix.de> (raw)
In-Reply-To: <2868543.tdWV9SEqCh@falcon9>
Hello Detlev,
Hello Shawn,
On 11.11.22 20:35, Detlev Casanova wrote:
> On Thursday, November 10, 2022 9:52:32 P.M. EST Shawn Guo wrote:
>> On Fri, Oct 28, 2022 at 10:18:11AM -0400, Detlev Casanova wrote:
>>> If not specified, the mmc0 and mmc1 devices will be the devices
>>> mmc@2190000 and mmc@2194000, which are in disabled state on the iMX.6
>>> Sabrelite devices.
>>>
>>> The actual SD card reader devices are the ones at mmc@2198000 and
>>> mmc@219c000.
>>>
>>> Set aliases to use the correct mmc devices order.
>>
>> Is this something never worked or a regression? For the latter, we may
>> need a Fixes tag?
>
> These were apparently never set in the kernel device-tree and added manually
> in u-boot when dts are synced.
>
> Because most distributions use UUIDs in fstab, it is not a big problem in
> Linux, just that the SD card is called /dev/mmcblk2. I would say that this has
> always been an issue in Linux.
We already have aliases in imx6qdl.dtsi. Existing Installations that hardcode
root=mmcblk2 _will_ be broken by this change. Installations that are fixed
by this change have never worked properly, because prior to commit fa2d0aa96941
("mmc: core: Allow setting slot index via device tree alias"), it depended
on probe order and/or whether a card was present.
Whether SD/eMMC comes first or if they start at 0 or 2 is just cosmetic.
The alias order corresponds with the order in the data sheet and that's a
good default and I see no reason to change this here and risk breakage.
I thus don't think this patch should go mainline.
Thanks,
Ahmad
>
>> Shawn
>>
>>> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
>>> ---
>>>
>>> arch/arm/boot/dts/imx6qdl-sabrelite.dtsi | 5 +++++
>>> 1 file changed, 5 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi
>>> b/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi index
>>> 22f8e2783cdf..12573e1f917c 100644
>>> --- a/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi
>>> +++ b/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi
>>> @@ -14,6 +14,11 @@ chosen {
>>>
>>> stdout-path = &uart2;
>>>
>>> };
>>>
>>> + aliases {
>>> + mmc0 = &usdhc3;
>>> + mmc1 = &usdhc4;
>>> + };
>>> +
>>>
>>> memory@10000000 {
>>>
>>> device_type = "memory";
>>> reg = <0x10000000 0x40000000>;
>
>
>
>
>
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
next prev parent reply other threads:[~2022-11-28 8:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-28 14:18 [PATCH] ARM: dts: imx6qdl-sabre: Add mmc aliases Detlev Casanova
2022-11-11 2:52 ` Shawn Guo
2022-11-11 19:35 ` Detlev Casanova
2022-11-28 8:42 ` Ahmad Fatoum [this message]
2022-11-14 8:25 ` Shawn Guo
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=a13c2e92-cfa6-04fd-c32a-c4d444894660@pengutronix.de \
--to=a.fatoum@pengutronix.de \
--cc=detlev.casanova@collabora.com \
--cc=devicetree@vger.kernel.org \
--cc=festevam@gmail.com \
--cc=kernel@pengutronix.de \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=robh+dt@kernel.org \
--cc=s.hauer@pengutronix.de \
--cc=shawnguo@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).