ide driver loses flash

[R. Luoma]

I have a system that runs off a RAM "disk" that occasionally
mounts a flash drive for reading and writing
and, when finished, unmounts the flash.

Every so often, the flash drive seems to disappear
and I cannot remount the flash partitions.

dmesg gives messages like:

> hda: status timeout: status=0xd0 { Busy }

> hda: no DRQ after issuing WRITE
> ide0: reset: master: error (0x00?)
> hda: status error: status=0x08 { DataRequest }

> hda: drive not ready for command
> hda: status error: status=0x00 { }

I can reboot the system and then access the flash again,
but rebooting is a rather drastic option for several reasons.

Can anyone suggests what might be going wrong
and how to fix it?

Thanks,
-- 
R. Luoma