pen-drive write cache turning off

[LeVA <leva@az.isten.hu>]

Hi!

I'm using linux kernel 2.6.11.6, and I have a pendrive (usb 1.0, the slower 
one ;). When I copy stuff to it, or delete stuff from it, it happens quickly. 
But after I umount it, my cpu usage is getting high, and I can see on my 
pendrive's led, that my system is now performing the read/write transactions.
My question is: can I control this write cache thru some /proc file, or with 
command line, or mount option, or kernel .config variable, or that's just the 
way it is, and I have to wait minutes after umounting my pendrive, so I can 
disconnect it?

Thanks!
Daniel


-- 
LeVA