Re: [PATCH] arm64: dts: meson: odroid-n2: keep SD card regulator always on

[Neil Armstrong <narmstrong@baylibre.com>]

Hi Anand,

On 24/07/2019 07:30, Anand Moon wrote:
> Hi All,
> 
> On Mon, 22 Jul 2019 at 12:51, Neil Armstrong <narmstrong@baylibre.com> wrote:
>>
>> 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
>>
> 
> I am afraid this did not fix the issue I was also facing with
> Archlinux on Odroid N2 using mainline u-boot.

Seems to be a separate issue, could we start a separate thread with all your
setup (branch, git SHAa, configs, board setup, ...) for this ?

Thanks,
Neil

> Here is the log of at my end using latest mainline u-boot with Neil's patches.
> 
> [0] https://pastebin.com/HNmeY5uF
> 
> Well this issue also persist with eMMC not getting detected after reboot
> If I try to change the dts to fix the sdcard.
> 
> I am checking this should we enable regulator-boot-on option but still no luck.
> 
> Best Regards
> -Anand
> 


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