Bug 22204

	
	During backups or any extended write sequence to the drive, the
	following will be produced:

ast0: WRITE command timeout - resetting
ata0: resetting devices .. ata0: mask=03 status0=00 status1=10
ata0-master: success setting PIO3 on generic chip
ata0-slave: timeout waiting for command=ef s=11 e=60
ata0-slave: failed setting PIO4 on generic chip
ata0-slave: using PIO mode set by BIOS
done
	At which point dump will abort write an I/O error
	Small backups work successfully; the drive probably recalibrates
	during a long dump, which makes for an extra long write cycle.

	Similarly, doing a mt retension will produce

ast0: TEST_UNIT_READY command timeout - resetting
ata0: resetting devices .. ata0: mask=03 status0=00 status1=10
ata0-master: success setting PIO3 on generic chip
ata0-slave: timeout waiting for command=ef s=11 e=60
ata0-slave: failed setting PIO4 on generic chip
ata0-slave: using PIO mode set by BIOS
done

	And return to the prompt with 'Input/output error'

	Tape drive and tape successfully pass a 8000M read/write test using
	the Seagate Diagnostics Utility 2.1 under DOS


	This is not specific to the ATA controller (an Aladdin chipset
	produces the same results).

How-To-Repeat: 
	Try a backup using that model tape drive.