Re: Unable to randomly boot rootfs (EXT3 or EXT4) from SD: MMC error -110 (TIMEDOUT)

["Kevyn-Alexandre Paré" <kevyn.alexandre.pare@gmail.com>]

Hi Ted,

On Tue, Aug 27, 2013 at 6:01 PM, Theodore Ts'o <tytso@mit.edu> wrote:
> On Tue, Aug 27, 2013 at 05:47:22PM -0400, Kevyn-Alexandre Paré wrote:
>> mmcblk0: error -110 sending status command, retrying
>> mmcblk0: error -110 sending status command, retrying
>> mmcblk0: error -110 sending status command, aborting
>
> This looks like a hardware problem; either with the MMC reader, or the
> MMC/SD card.

That's what I thought, thanks.

>
> Can you try swapping out the hardware and see if the problem goes
> away?

We try multiple of our system ( Different micro SD from SanDisk +
Overo with OMAP3) and they are all doing this with the SanDisk 64GB,
32GB :
http://www.sandisk.com/products/memory-cards/microsd/ultra-class10-for-android/?capacity=64GB

The problem seem to be easier to reproduce when we just flash the
micro SD (partition, format & copy rootfs) at it first boot.
Also, when we let the system down for a couple of days and then
sometimes we need to reboot the system multiple times before it fall
back alright.

We found a old patch that was simply increasing the timeout of the host:
http://cgit.openembedded.org/cgit.cgi/openembedded/tree/recipes/linux/linux-omap-2.6.39/sakoman/0024-omap-mmc-Adjust-dto-to-eliminate-timeout-errors.patch?h=org.openembedded.dev

By settings the timeout to zero I reproduce kind of the same timeout
error at every boot. That was expected since I don't let enough time
to the controller to respond...

Could the mix of that MMC controller and these card is not optimal? Is
the driver fully supporting the UHS-I speed grade?

Regards,

-KA

>
>                                                 - Ted