Matthias Brugger [off-list ref] writes:

On 12/02/16 16:24, Matthias Brugger wrote:

quoted

Hi Kevin,

On 09/02/16 02:18, Kevin Hilman wrote:

quoted

Hello,

I tried getting MMC working with linux-next (next-20160208) on
mt8173-evb by enabling a few options[1] on top of the default defconfig,
and this results in a kernel that hangs as soon as it starts userspace.

The MMC driver seems to start, though has some regulator issues:

[    0.526380] sdhci: Secure Digital Host Controller Interface driver
[    0.527176] sdhci: Copyright(c) Pierre Ossman
[    0.528835] vio18: unsupportable voltage range: 3300000-1980000uV
[    0.529610] mtk-msdc 11230000.mmc: Regulator set error -22:
3300000 - 3300000
[    0.563731] mtk-msdc 11240000.mmc: Got CD GPIO

The driver appears to be attempting to set 3.3V but using a 1.8V
regulator (vio18), which is failing.

Then, the kernel hangs after freeing unused memory:

[    0.616386] hctosys: unable to open rtc device (rtc0)
[    0.624118] usb_vbus: disabling
[    0.624547] vusb: disabling
[    0.624929] vgp6: disabling
[    0.625635] ALSA device list:
[    0.626009]   No soundcards found.
[    0.626963] Freeing unused kernel memory: 724K (ffffffc000977000 -
ffffffc000a2c000)

And nothing further here.

I can see the warning from the mmc regulator access, but after that my
board boots just fine.
I'm using linux-next as of today (20160212).
I attached my config, it should be defconfig plus the config options you
mentioned (and an initramfs).

Is this the configuration you have?

I spotted an error in my scripts to build the kernel. After fixing
this I can reproduce your error.

OK, let me know if you need anything else to help debug, or want me to
test anything further.  Otherwise I'll leave it in your capable hands.

Kevin