Recently, i have a problem related to mass storage mode - after doing several tests i am able to reproduce this behavior every time:

After restart to the N900, i connect it in mass storage mode, and both mmc and mydocs becomes accessible from my pc.

after i disconnect from mass storage mode and reconnect again, only MyDocs is available and i get this message:

"Only device storage connected, Memory card already in use"

I am unable to access mmc card again in mass storage mode until i restart (it is accessible from the n900 after i disconnect mass storage and not accessible after it is connected again - so it seems that the mass storage mode actually dismounts the card, but still i cannot access it from the pc).

Anyone knows how to debug/fix this issue?

Try the mount -l command on the mmc directory before trying to mount?

i'm not sure i understand what you mean.

-l is an option of umount - not mount, and the problem i'm having is not mounting the mmc, but dismounting it + recognizing it in mass storage mode from the PC.

If I understand it correctly, yo ucan always access the mmc card from N900, but from PC only after a reboot, right? If so, try manually unmount (with umount -l) the mmc card before you try to connect it to a pc after second time.

If it is inaccesible from the PC, it probably means it is still mounted somehow on N900.

Maybe something is accessing the memory card.
Try "lsof | grep mmc1" and "ls -lR /proc/ | grep mmc1> tmp;clear; cat tmp;rm tmp"

Before connecting the usb cable and activating mass storage mode:
"lsof | grep mmc1" returns empty

Output of:
"ls -lR /proc/ | grep mmc1> tmp;clear; cat tmp;rm tmp" is empty also:

/proc/irq/86/mmc1:
[root ~]#

Output of:
"lsof /dev/media/" is "lsof: status error on /dev/media: No such file or directory"

Also, as I described in post #31 - after connecting the cable and activating mass storage mode, I can see that there are no files in /media/mmc1(and I also get the error mentioned "Only device storage connected, Memory card already in use")

if I disconnect the cable, I can see the card files again in /media/mmc, which I think shows that the mount/dismount worked correctly by mass storage mode.

I can also freely mount and umount mmc using the following with no errors (which causes the files in /media/mmc1 to be accessible/inaccessible):

mount /dev/mmcblk1p1 /media/mmc1
umount -f -l /media/mmc1

Are you "safely removing" the n900 from your host PC? I sometimes get this problem if I don't.

You can also try running
sudo /usr/sbin/osso-usb-mass-storage-disable.sh
and connect to pc again.

I don't know if it's useful info for current on-topic problem, but I got different "unknown" behavior - after successfully connecting device in mass storage once, (and removing safely), MyDocs isn't accesible for device. No big deal - I've created script that mount it again after disconnect. Furthermore, while being connected, MMC (microSD) is accessible for *both* desktop and N900 (that is, mounted simultaneously).

I can connect it again to desktop PC, yet, only for limited amount of time. After few hours (wasn't able to detect it precisely), connecting device result in charging only - HUBS with diode lighting up doesn't show any device connected, desktop OS'es doesn't act like seeing anything, etc. I've tried many tricks with osso-usb-mass-storage-enable.sh etc, to no avail. Only restart fix this problem.

I'm perfectly sure, that nothing is accessing it, also, it isn't mounting problem - device isn't recognized as USB gadget at all.

/Estel

Safely removing the device does not help - same issue.

/usr/sbin/osso-usb-mass-storage-disable.sh does not help also...