Tejun Heo wrote:
John Clark wrote:
Hello,
I've discovered an issue with the Quantum CD72SH SATA tape drive. I set
it to variable block size, try to write a 5317 byte block with an ATAPI
issued WRITE(6), and it hangs. The drive is connected to an Intel ICH9R
in AHCI mode.
My debugging efforts have determined that it's a problem with the
drive's firmware. It does not like ATAPI CDBs with odd (& 1) transfer
lengths with PIO. If I let it use DMA, even if it's not a multiple of
16 bytes, then it seems to work:
--- libata-core.c.orig 2008-09-27 16:12:46.000000000 -0400
+++ libata-core.c 2008-09-27 16:11:29.000000000 -0400
@@ -4669,8 +4669,8 @@
/* Don't allow DMA if it isn't multiple of 16 bytes. Quite a
* few ATAPI devices choke on such DMA requests.
*/
- if (unlikely(qc->nbytes & 15))
- return 1;
+ // if (unlikely(qc->nbytes & 15))
+ // return 1;
if (ap->ops->check_atapi_dma)
return ap->ops->check_atapi_dma(qc);
This is an acceptable solution for my limited use, but I'd like to see
it work out of the box. It seems frightening that there are ATAPI
devices out there that choke on PIO requests. What would you like to do?
We can create a HORKAGE for it. Can you please post the result of
"hdparm -I" of the device?
Tejun,
Here it is:
/dev/nst0:
ATAPI Sequential-access device, with removable media
Model Number: QUANTUM DAT DAT72-000
Serial Number: JR001H1
Firmware Revision: VC090000
Standards:
Used: ATA/ATAPI-7 T13 1532D revision 4a
Supported: 7 6 5 4
Configuration:
DRQ response: 50us.
Packet size: 12 bytes
Capabilities:
LBA, IORDY(can be disabled)
DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120ns
Commands/features:
Enabled Supported:
* Power Management feature set
* PACKET command feature set
* DEVICE_RESET command
* NOP cmd
* SATA-I signaling speed (1.5Gb/s)
Integrity word not set (found 0x0000, expected 0x6da5)
Thank you.
- John
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