On 10/15/2013 06:11 PM, Dan Williams wrote:
On Tue, Oct 15, 2013 at 5:15 PM, Praveen Murali <pmur...@logicube.com> wrote:
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.
Looks like a latent bug in libsas to me. Commit 110dd8f1 "[SCSI]
libsas: fix scr_read/write users and update the libata documentation"
looks like a compile fix when the build was broken by commit 9977126c
"libata: add @is_cmd to ata_tf_to_fis()" where libata changed the
interface for ata_tf_to_fis(). We were passing 0 for pmp prior to
that and changed to 1 here, probably a typo intending 'is_cmd to
always be 1.
Somehow we have gotten away with is_cmd being 0? Does the following
patch work for you:
diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 161c98efade9..d0fb99d5da95 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -211,7 +211,7 @@ static unsigned int sas_ata_qc_issue(struct
ata_queued_cmd *qc)
qc->tf.nsect = 0;
}
- ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
+ ata_tf_to_fis(&qc->tf, qc->dev->link->pmp, 1, (u8*)&task->ata_task.fis);
task->uldd_task = qc;
if (ata_is_atapi(qc->tf.protocol)) {
memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
Hi Dan,
I tested this patch and it works great!
Thanks,
Praveen
That being said I don't think anybody has really checked out
port-multiplier support on libsas, but we shouldn't be setting this
bit by default.
--
Dan
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).
I assume the first IDENTIFY is coming from the BIOS, not Linux correct?
- 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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