hmm,

are you properly unmounting the device before you pull it? i have seen cranky behavior from drivers that are holding on to a device that anchors a filesystem mount-point.

there was also a rash of strange usb bugs in the earlier 3.x kernels, but iirc they didn't creep in until 3.1...

-steve

On 02/29/2012 10:34 AM, Klaus-Hendrik Wolf wrote:
Hi Steve,

yes, i need to run this on a Linux box, so the Windows stuff does not
help in this special case, but i will try whether it is reproducible
there as well.

We do use only sandisk cards for all our shimmers. And they do work
perfect from the shimmer-point of view. With justfatlogger data get
written to the card, as i can confirm with another sdcard reader (and
sometimes via the dock as well ;-))

The box runs a not quite current, but recent version of Ubuntu.
Ubuntu 11.10 (GNU/Linux 3.0.0-14-generic x86_64)

Linux version 3.0.0-14-generic (buildd@allspice)
(gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3) )
#23-Ubuntu SMP Mon Nov 21 20:28:43 UTC 2011
(Ubuntu 3.0.0-14.23-generic 3.0.9)

Regarding syslog i see the following when the mount works:

[87798.247862] sd 20:0:0:0: [sdb] 3911680 512-byte logical blocks: (2.00
GB/1.86 GiB)
[87798.259683] sd 20:0:0:0: [sdb] No Caching mode page present
[87798.259693] sd 20:0:0:0: [sdb] Assuming drive cache: write through
[87798.275806] sd 20:0:0:0: [sdb] No Caching mode page present
[87798.275816] sd 20:0:0:0: [sdb] Assuming drive cache: write through
[87798.278845] sdb: sdb1
[87898.015520] sdb: detected capacity change from 2002780160 to 0

And if it is not recognized, there simply is nothing.

As far as i understood the linux world udev handles the assignment of
device drivers and if i do not see anything in udev-monitor nothing
should be in syslog? (Just to help me understand and use the best tool
to find the problem).

Thanks!

Klaus Hendrik

Am 29.02.2012 16:00, schrieb steve ayer:
hi klaus,

i just noticed that you're running udevadm. have you tried tailing
syslog, which may give you a bit more detail as to what's happening?

oh, and what kernel are you running?

-steve

On 02/29/2012 06:02 AM, Klaus-Hendrik Wolf wrote:
Dear all,

For one of our new settings we would like to use the shimmer as a
recording device only and have the subjects collect the data from the SD
card via an USB connected dock.

During our testing we came across a problem which hopefully you know how
to solve or work around.

Inserting the shimmer into the dock *sometimes* results in it being
discovered by the connected computer as a new medium in the
corresponding block device (monitored with udevadm monitor).
With my latest tests this *sometimes* unfortunately means: not very
often.

We first discovered this behavior with our own firmware, but it is
reproducible with the justfatlogging app as well. I have tested at least
four different shimmers (2r), so it should not be a hardware problem.

I tried different combinations of resetting the shimmer (in and out of
the dock), disconnecting and reconnecting the dock (shimmer in and out),
but found no combination that is working in most cases.

A work-around for justfatlogging i have found is to remove the SD card,
reset the shimmer, insert the card and after that put it in the dock.

But disassembling and removing the SD card is not really an option for
our study.

Does anyone of you have an idea how to make docking more reliable?
If it is only one out of three it would still be OK.
Even a workaround would be welcome! (As long as it does not involve
opening the shimmer)

Best regards,

Klaus Hendrik
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