From: Neil Armstrong <narmstrong@baylibre.com>
To: Xavier Ruppen <xruppen@gmail.com>, khilman@baylibre.com
Cc: martin.blumenstingl@googlemail.com,
linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm64: dts: meson: odroid-n2: keep SD card regulator always on
Date: Mon, 22 Jul 2019 09:21:40 +0200 [thread overview]
Message-ID: <eadcf7ef-4aad-fa4f-3b1b-a5238f394b1e@baylibre.com> (raw)
In-Reply-To: <20190719192954.26481-1-xruppen@gmail.com>
On 19/07/2019 21:29, Xavier Ruppen 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>
> ---
>
> 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].
>
> 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.
>
> [1] https://forum.odroid.com/viewtopic.php?f=176&t=33993
>
> arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> index 81780ffcc7f0..4e916e1f71f7 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> @@ -53,6 +53,7 @@
>
> gpio = <&gpio_ao GPIOAO_8 GPIO_ACTIVE_HIGH>;
> enable-active-high;
> + regulator-always-on;
> };
>
> tf_io: gpio-regulator-tf_io {
>
Surely solves the situation, thanks !
please add a comment on top of "regulator-always-on" to explain why we always enable it,
note we should always enable it in case of watchdog reboot or other uncontrolled reset,
this regulator must never be disabled.
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Thanks,
Neil
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next prev parent reply other threads:[~2019-07-22 7:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-19 19:29 [PATCH] arm64: dts: meson: odroid-n2: keep SD card regulator always on Xavier Ruppen
2019-07-22 7:21 ` Neil Armstrong [this message]
2019-07-24 5:30 ` Anand Moon
2019-07-24 6:49 ` Neil Armstrong
2019-07-24 9:00 ` Anand Moon
2019-07-23 19:48 ` Martin Blumenstingl
2019-07-25 23:41 ` Kevin Hilman
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