libata-pmp: clear hob for pmp register accesses
>> Mark Lord wrote:
>>> Tejun, I've added PMP to sata_mv, and am now trying to get it
>>> to work with a Marvell PM attached.
>>>
>>> And the behaviour I see is very bizarre.
>>>
>>> After hard+soft resets, the PM signature is found,
>>> and libata interrogates the PM registers.
>>>
>>> It successfully reads register 0, and then register 1.
>>> But all subsequent registers read out (incorrectly) as zeros.
...
This behavior has been confirmed by Marvell with a SATA analyzer.
The Marvell port-multiplier apparently likes to see clean HOB
information when accessing PMP registers.
Since sata_mv uses PIO shadow register access, this doesn't happen
automatically, as it might in a more purely FIS-based driver (eg. ahci).
One way to fix this is to flag these commands with ATA_TFLAG_LBA48,
forcing libata to write out the HOB fields with known (zero) values.
Signed-off-by: Saeed Bishara <saeed@marvell.com>
Acked-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index caef2bb..d91f509 100644
--- a/drivers/ata/libata-pmp.c
+++ b/drivers/ata/libata-pmp.c
@@ -35,7 +35,7 @@
ata_tf_init(pmp_dev, &tf);
tf.command = ATA_CMD_PMP_READ;
tf.protocol = ATA_PROT_NODATA;
- tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
+ tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
tf.feature = reg;
tf.device = link->pmp;
@@ -71,7 +71,7 @@
ata_tf_init(pmp_dev, &tf);
tf.command = ATA_CMD_PMP_WRITE;
tf.protocol = ATA_PROT_NODATA;
- tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
+ tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48;
tf.feature = reg;
tf.device = link->pmp;
tf.nsect = val & 0xff;