Dan/James,
Can you please take a look at this and let me know if I am at the
right place? Or point me in the right direction? As I understand, this
deost not look like an mvsas driver issue.
Thanks,
Praveen
On 10/14/2013 05:18 PM, Praveen Murali wrote:
Hi,
I have couple of external drives (Western Digital and Seagate) that
have an eSATA interface. My Linux box with a Marvell HBA (9445)
running Ubuntu 12.04 with 3.2.48 kernel doest not seem to detect the
drive. I tried with the latest upstream kernel and it behaves the
same. But both the drives detect fine if I enter the mvsas BIOS during
bootup. So I have hooked up a SATA analyzer and this is what I found
- When I tried to detect the drives in the mvsas BIOS, all the ATA
commands that the bios issues have the port multiplier byte set to 0.
- If I bootup my Linux system and then connect the drives, the first
IDENTIFY command has the port multiplier set to 0 (this one is
successful) and the subsequent IDENTIFY command has port multiplier
set to 1 (this one fails).
- If I connect any other SATA drives I have to the HBA, all the ATA
commands have port multiplier set to 1 but they detects and work fine.
Just to rule out the port-multiplier possibility I changed the
following line in drivers/scsi/libsas/sas_ata.c - fucntion
sas_ata_qc_issue()
ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
to
ata_tf_to_fis(&qc->tf, 0, 0, (u8*)&task->ata_task.fis);
now all my drives seem to detect just fine. I believe, the eSATA
interface on these external drives is a port multiplier, which is why
the command fails. Also, the normal drives ignore this field thats why
they work fine with port multiplier being set to either 0 or 1.
Question(s): Are my above assumtions correct? If so, what is the
reasoning behind setting the port multiplier to 1 by default in libsas
layer?
Thanks,
Praveen
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