Second SD card on RPi3 CM3 on Ubuntu Core 18 does not work

[Philip Vanloo]

As suggested in following thread;

https://forum.snapcraft.io/t/second-sd-card-on-rpi3-cm3-with-ubuntu-core-18/10465

a bug report.

The configuration works for a Ubuntu Core 16 device.

[Philip Vanloo (fragiledj)]

Could someone please take a look at this?

For the record, running pi-kernel with track 18-cm3

[Paolo Pisati (p-pisati)]

Can you add all the relevant information here?

How to reproduce the issue (kernel version pre & post regression), hardware used (cpu board, io board), an accurate description of the issue (what *exactly* was working before the regression, what didn't work after the breakage, etc), any other relevant information, etc.

[Philip Vanloo (fragiledj)]

Hi

To start off, I was using Ubuntu Core 16 on a custom-designed board that houses a RPi CM3.

This board has some peripherals such as USB, ethernet and a SD card, all of them worked.

The kernel version I used on Ubuntu Core 16 was 4.4.0-1109.117 (snap is pi2-kernel tracking stable).

Now I wanted to make the switch to Ubuntu Core 18, using the same overlays and configuration files, but the SD card no longer works, dmesg shows

[ 4.062885] sdhci: Secure Digital Host Controller Interface driver
[ 4.062888] sdhci: Copyright(c) Pierre Ossman
[ 4.063074] mmc-bcm2835 3f300000.sdio: could not get clk, deferring probe
[ 4.063288] sdhost-bcm2835 3f202000.mmc: could not get clk, deferring probe
[ 4.063344] Error: Driver 'sdhost-bcm2835' is already registered, aborting...
[ 4.063353] sdhci-pltfm: SDHCI platform and OF driver helper
[ 4.134639] mmc-bcm2835 3f300000.sdio: mmc_debug:0 mmc_debug2:0
[ 4.134645] mmc-bcm2835 3f300000.sdio: DMA channel allocated
[ 4.171639] sdhost: log_buf @ d033dd8b (fa047000)
[ 4.239344] mmc0: sdhost-bcm2835 loaded - DMA enabled (>1)

According to the snap version, the kernel I'm using is 4.15.0-1036.38 (snap is pi-kernel tracking 18-pi3).

[Philip Vanloo (fragiledj)]

Any clues on what I should start looking for?

[Philip Vanloo (fragiledj)]

Anyone?

[Launchpad Janitor (janitor)]

[Expired for linux-raspi2 (Ubuntu) because there has been no activity for 60 days.]

[Juerg Haefliger (juergh)]

Can you please post a complete kernel log?

[Philip Vanloo (fragiledj)]

Thanks for following up, here's the log from dmesg.
I've removed some audit logs that are non-applicable.

[Juerg Haefliger (juergh)]

OK thanks. And what's the problem? Seems the Pi is booting up just fine.

If you want to talk we're on IRC freenode #ubuntu-kernel. My nick is juergh.

[Juerg Haefliger (juergh)]

I've added an SD card slot to my Raspberry CMIO board and verified that the SD card shows up when using the latest Raspbian image and the dtoverlay=sdio config.txt option. Seems to work fine.

Then installed Ubuntu Core 16, added dtoverlay=sdio, verified that /proc/device-tree shows the overlay but no further luck. The SD card does not show up. Am I missing something? Can you verify that it works for you with latest core 16 and kernel 4.4.0-1126-raspi2?

[Philip Vanloo (fragiledj)]

I've just checked this:

core 16-2.42.1 8043 stable canonical✓ core
core18 20191030 1267 stable canonical✓ base
pi2-kernel 4.4.0-1124.133 102 stable canonical✓ kernel

[1579563.933197] mmc1: host does not support reading read-only switch, assuming write-enable
[1579563.935491] mmc1: new high speed SDHC card at address 59b4
[1579563.938350] mmcblk1: mmc1:59b4 SMI 3.75 GiB
[1579563.940381] mmcblk1:

---------

snap refresh pi2-kernel --candidate

core 16-2.42.1 8043 stable canonical✓ core
core18 20191030 1267 stable canonical✓ base
pi2-kernel 4.4.0-1126.135 104 candidate canonical✓ kernel

[ 46.689610] mmc1: Timeout waiting for hardware interrupt.
[ 46.697435] mmc1: error -110 whilst initialising SD card
[ 47.788757] mmc1: invalid bus width
[ 47.792460] mmc1: error -22 whilst initialising SD card
[ 47.873646] mmc1: invalid bus width
[ 47.877267] mmc1: error -22 whilst initialising SD card

[Juerg Haefliger (juergh)]

In my case I don't get anything in the logs indicating that the kernel is trying to talk to mmc1.

$ dmesg | grep mmc
[ 4.594995] mmc0: sdhost-bcm2835 loaded - DMA enabled (>1)
[ 4.603742] mmc-bcm2835 3f300000.mmc: mmc_debug:0 mmc_debug2:0
[ 4.610786] mmc-bcm2835 3f300000.mmc: DMA channel allocated
[ 4.706210] mmc0: host does not support reading read-only switch, assuming write-enable
[ 4.805580] mmc0: new high speed SDHC card at address aaaa
[ 4.806124] mmcblk0: mmc0:aaaa SL32G 29.7 GiB
[ 4.817997] mmcblk0: p1 p2
[ 5.574715] EXT4-fs (mmcblk0p2): couldn't mount as ext3 due to feature incompatibilities
[ 5.589925] EXT4-fs (mmcblk0p2): couldn't mount as ext2 due to feature incompatibilities
[ 5.620475] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: errors=remount-ro
[ 5.709751] EXT4-fs (mmcblk0p2): couldn't mount as ext3 due to feature incompatibilities
[ 5.725000] EXT4-fs (mmcblk0p2): couldn't mount as ext2 due to feature incompatibilities
[ 5.754792] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[ 6.399854] FAT-fs (mmcblk0p1): IO charset ascii not found

$ snap list
Name Version Rev Tracking Publisher Notes
cm3 16.04-0.7 7 edge canonical✓ gadget
core 16-2.42.2+git1570.35c66d9 8199 edge canonical✓ core
nano 3.2+pkg-24de 29 stable snapcrafters -
pi2-kernel 4.4.0-1126.135 104 edge canonical✓ kernel

$ find /proc/device-tree/ | grep sdio
/proc/device-tree/soc/gpio@7e200000/sdio_pins
/proc/device-tree/soc/gpio@7e200000/sdio_pins/name
/proc/device-tree/soc/gpio@7e200000/sdio_pins/phandle
/proc/device-tree/soc/gpio@7e200000/sdio_pins/brcm,function
/proc/device-tree/soc/gpio@7e200000/sdio_pins/brcm,pins
/proc/device-tree/soc/gpio@7e200000/sdio_pins/brcm,pull
/proc/device-tree/soc/gpio@7e200000/sdio_pins/linux,phandle

[Philip Vanloo (fragiledj)]

Indeed

$ find /proc/device-tree/ | grep sdio
/proc/device-tree/soc/gpio@7e200000/sdio_pins
/proc/device-tree/soc/gpio@7e200000/sdio_pins/name
/proc/device-tree/soc/gpio@7e200000/sdio_pins/phandle
/proc/device-tree/soc/gpio@7e200000/sdio_pins/brcm,function
/proc/device-tree/soc/gpio@7e200000/sdio_pins/brcm,pins
/proc/device-tree/soc/gpio@7e200000/sdio_pins/brcm,pull
/proc/device-tree/soc/gpio@7e200000/sdio_pins/linux,phandle

However I'm using dtoverlay=sdio,poll_once=off
Does the poll_once change anything?

On Ubuntu Core 18 find /proc/device-tree | grep sdio
Shows empty

[Philip Vanloo (fragiledj)]

This issue is resolved when using pi-kernel track 18-pi/stable (e.g. 5.3.0-1018.20~18.04.1), however such a version is not yet pushed to 18-cm3

[Juerg Haefliger (juergh)]

As mentioned on IRC, going forward there will only be a single channel 18-pi.

Also, since this problem is resolved in the 5.x kernel, I'm going to mark this bug as resolved. If someone needs this with the 4.15 kernel or with core16, please open a new ticket and we'll evaluate it.