Hi, I just what to make it clear that this is not a bug of the Marvell's PM, the sata specification (I'm looking at version 2.5) defines the READ/WRITE PM registers to be extended commands, specifically, the features HOB of the READ PM register defined to be RegNum[15:8]. saeed On Thu, Feb 21, 2008 at 10:52 PM, Mark Lord <liml@xxxxxx> wrote: > Mark Lord wrote: > > Tejun Heo wrote: > >> Hello, Mark. > >> > >> 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. > .. > > Saeed has confirmed this behaviour 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@xxxxxxxxxxx> > Acked-by: Mark Lord <mlord@xxxxxxxxx> > --- > drivers/ata/libata-pmp.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > 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 @@ static unsigned int sata_pmp_read(struct ata_link *link, int reg, u32 *r_val) > 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 @@ static unsigned int sata_pmp_write(struct ata_link *link, int reg, u32 val) > 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; > - > To unsubscribe from this list: send the line "unsubscribe linux-ide" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
