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

From: Ondrej Zary
Date: Thu Jul 02 2015 - 12:20:21 EST


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
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