Re: [PATCH] ARM: dts: imx6qdl-sabre: Add mmc aliases

From: Detlev Casanova <detlev.casanova@collabora.com>
To: Shawn Guo <shawnguo@kernel.org>
Cc: linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>,
	"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: Fri, 11 Nov 2022 14:35:36 -0500	[thread overview]
Message-ID: <2868543.tdWV9SEqCh@falcon9> (raw)
In-Reply-To: <20221111025232.GI125525@dragon>

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.

> 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>;