Re: 2.6.20 libata cdrom

[William Thompson <wt@electro-mechanical.com>]

On Mon, Apr 30, 2007 at 12:22:21PM +0200, Tejun Heo wrote:
> William Thompson wrote:
> > I've been playing with libata on a few machines and I found that this machine
> > (An old Dell Dimension L866r) gives me this when it loads and does not give me
> > access to the cdrom.  This is the only machine that I've tested that I know
> > for a fact cannot do DMA on the cdrom.  I searched and noticed a similar
> > problem with 2.6.19-rc versions but I'm not sure if it's the same problem.
> > 
> > dmesg output:
> > libata version 2.00 loaded.
> > ata_piix 0000:00:1f.1: version 2.00ac7
> > PCI: Setting latency timer of device 0000:00:1f.1 to 64
> > ata1: PATA max UDMA/66 cmd 0x1F0 ctl 0x3F6 bmdma 0xFFA0 irq 14
> > ata2: PATA max UDMA/66 cmd 0x170 ctl 0x376 bmdma 0xFFA8 irq 15
> > scsi0 : ata_piix
> > ata1.00: ATA-4, max UDMA/33, 10018890 sectors: LBA
> > ata1.00: ata1: dev 0 multi count 16
> > ata1.00: configured for UDMA/33
> > scsi1 : ata_piix
> > ata2.00: failed to IDENTIFY (I/O error, err_mask=0x1)
> 
> Hmm... IDENTIFY failed on the second port.  How reproducible is the
> problem?  Every time?  Does it work with the IDE driver?  If so, please
> post the result of 'hdparm -I /dev/hdX'.

Reproducible?  Everytime

Yes, it works fine with the IDE driver, so long as DMA is disabled.

hdparm -I:
/dev/hdc:

ATAPI CD-ROM, with removable media
        Model Number:           Lite-On LTN483S 48x Max
        Serial Number:
        Firmware Revision:      PD02
Standards:
        Used: ATAPI for CD-ROMs, SFF-8020i, r2.5
        Supported: CD-ROM ATAPI-1
Configuration:
        DRQ response: <=10ms with INTRQ
        Packet size: 12 bytes
Capabilities:
        LBA, IORDY(can be disabled)
        DMA: sdma0 sdma1 sdma2 mdma0 mdma1 mdma2 udma0 udma1 *udma2
             Cycle time: min=120ns recommended=120ns
        PIO: pio0 pio1 pio2 pio3 pio4
             Cycle time: no flow control=120ns  IORDY flow control=120ns