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From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Tue, 23 Jul 2019 21:48:33 +0200
Message-ID: <CAFBinCDRHbsDPe58qCfOzM_mZ+tmZpg2=dbfWcHntCn4xajOdw@mail.gmail.com>
Subject: Re: [PATCH] arm64: dts: meson: odroid-n2: keep SD card regulator
 always on
To:     Xavier Ruppen <xruppen@gmail.com>
Cc:     khilman@baylibre.com, linux-amlogic@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Neil Armstrong <narmstrong@baylibre.com>
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On Fri, Jul 19, 2019 at 9:29 PM Xavier Ruppen <xruppen@gmail.com> wrote:
>
> When powering off the Odroid N2, the tflash_vdd regulator is
> automatically turned off by the kernel. This is a problem
> when issuing the "reboot" command while using an SD card.
> The boot ROM does not power this regulator back on, blocking
> the reboot process at the boot ROM stage, preventing the
> SD card from being detected.
>
> Adding the "regulator-always-on" property fixes the problem.
>
> Signed-off-by: Xavier Ruppen <xruppen@gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

> ---
>
> Here is what the boot ROM output looks like without this patch:
>
>     [root@alarm ~]# reboot
>     [...]
>     [   24.275860] shutdown[1]: All loop devices detached.
>     [   24.278864] shutdown[1]: Detaching DM devices.
>     [   24.287105] kvm: exiting hardware virtualization
>     [   24.318776] reboot: Restarting system
>     bl31 reboot reason: 0xd
>     bl31 reboot reason: 0x0
>     system cmd  1.
>     G12B:BL:6e7c85:7898ac;FEAT:E0F83180:2000;POC:F;RCY:0;
>     EMMC:800;NAND:81;SD?:0;SD:400;USB:8;LOOP:1;EMMC:800;
>     NAND:81;SD?:0;SD:400;USB:8;LOOP:2;EMMC:800;NAND:81;
>     SD?:0;SD:400;USB:8;LOOP:3; [...]
>
> Other people can be seen having this problem on the odroid
> forum [1].
thank you for submitting this patch (and not keeping it to yourself)!

> The cause of the problem was found by Martin Blumenstingl
> on #linux-amlogic. We may want to add his Suggested-by tag
> if he agrees.
yes, if you re-send this patch to address Neil's comment then feel
free to add my Reviewed-by as well as a Suggested-by


Martin