Re: IDE Floppy support for IOMEGA Zip Drive broken in 3.16 -> 3.17 transition

[Ondrej Zary <linux@rainbow-software.org>]

On Thursday 25 June 2015 22:58:58 Sergio Callegari wrote:
> Hi,
>
> I have an Iomega IDE Zip drive as in:
>
> /dev/sda:
>
>  Model=IOMEGA  ZIP 100       ATAPI       Floppy, FwRev=12.A, SerialNo=
>  Config={ SpinMotCtl Removeable nonMagnetic }
>  RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
>  BuffType=unknown, BuffSize=unknown, MaxMultSect=0
>  (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
>  IORDY=on/off, tPIO={min:500,w/IORDY:180}
>  PIO modes:  pio0 pio1 pio2 pio3
>  AdvancedPM=no
>
>  * signifies the current active mode
>
>
> ATAPI Direct-access device, with removable media
>         Model Number:       IOMEGA  ZIP 100       ATAPI       Floppy
>         Serial Number:
>         Firmware Revision:  12.A
> Standards:
>         Likely used: 4
> Configuration:
>         DRQ response: <=10ms with INTRQ
>         Packet size: 12 bytes
>         cache/buffer size  = unknown
> Capabilities:
>         LBA, IORDY(can be disabled)
>         DMA: not supported
>         PIO: pio0 pio1 pio2 pio3
>              Cycle time: no flow control=500ns  IORDY flow control=180ns
>                 Removable Media Status Notification feature set supported
> Security:
>                 supported
>                 enabled
>         not     locked
>         not     frozen
>         not     expired: security count
>
>                 supported: enhanced erase
>
>         Security level high
>
> The drive used to work just fine up to 3.16.  After a kernel upgrade, the
> drive started giving issues.  Some checks let me be sure that the issue
> does not exist with 3.16 and exists with 3.17.
>
> The problem manifests with IOWAIT all of a sudden jumping high (approx 50%)
> and staying high, even with the Iomega Zip drive unmounted. When this
> happens any activity having to do with the drive hangs (even hdparm -i
> /dev/sda). No related message in syslog apart from the indication of hung
> processes. Detaching the drive makes the machine behave properly.
>
> What has changed wrt IDE in 3.16->3.17 transition? Why is the issue present
> even when the drive is not used (unmounted)?  How can I help diagnosing?

You're probably using libata and not the old IDE layer.

Just tested this one:

 Model=IOMEGA  ZIP 100       ATAPI, FwRev=03.H, SerialNo=
 Config={ SpinMotCtl Removeable nonMagnetic }
 RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
 BuffType=unknown, BuffSize=unknown, MaxMultSect=0
 (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
 IORDY=on/off, tPIO={min:500,w/IORDY:180}, tDMA={min:150,rec:150}
 PIO modes:  pio0 pio1 pio2 pio3
 DMA modes:  mdma0 *mdma1
 AdvancedPM=no

 * signifies the current active mode

in 4.0.0-next-20150415 and it seems to work fine. Mounted, unmounted, read 
complete disk using dd without any problems.

-- 
Ondrej Zary