Bad DVD media causing UDMA step-down

ettlz · #1 16th August 2007, 09:25 PM

A rogue DVD+RW has provoked ata_piix into dropping the UDMA mode on my DVD+RW drive to UDMA/25 (should be UDMA/33):

Code:

ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen
ata2.00: cmd a0/01:00:00:00:00/00:00:00:00:00/a0 tag 0 cdb 0xac data 8 in
         res 40/00:03:00:00:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata2: soft resetting port
ata2.00: configured for UDMA/25
ata2: EH complete

Anyone know how to reset it without rebooting?

I've seen this before in the pre-libata days, and it's bit irritating to say the least. Why isn't the driver reset every time new media is inserted (i.e., removable drive => will see failing media but shouldn't hose the session)?