IGEL DOC2000 flash driver performance

[Jon Burford]

I have been using the IGEL flash driver on a Linux 2.2.12 system now for several months.  One very annoying "feature" is that it causes the entire OS to hang for 2-5 seconds after mounting or moderate write operations.  I talked with an M-Systems tech and although they did not write the driver, he thought it might be due to the garbage collection running in the DOC2000 firmware.  When a block becomes some configurable percentage utilized, the garbage collector tries to coallesce the used portion of this block with others to decrease block fragmentation and increase wearability.  His theory was that the driver would request space for a particular write operation and if garbage collection was necessary, the write operation would block.  My problem is that when this happens and the blocking lasts for > 1.5 seconds, my watchdog refresh process can't pet the watchdog and the system resets.  I have tried making the watchdog process a real-time thread with RTLinux, but the RTLinux beta11 is proving to be a little unstable for my blood right now.  I am wondering if anyone has encountered this problem and/or may have some advice for me.  Does the MTD DOC2000 driver suffer from this behavior and can it be patched into a 2.2.12 kernel?  Any other thoughts?

TIA!

Regards,
Jon
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