[PATCH] sata_mv: Manage SATA port multiplier while searching for active links

[PATCH] sata_mv: Manage SATA port multiplier while searching for active links

[Gregory CLEMENT]

From: Nadav Haklai <nadavh@marvell.com>

With this patch, when searching for active link, first search through
the port multiplier links. And then fall to the default ap active_tag
only if no there is no active link in the port multiplier.

[gregory.clement@free-electrons.com: reword commit log and title]

Signed-off-by: Lior Amsalem <alior@marvell.com>
Reviewed-by: Nadav Haklai <nadavh@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
 drivers/ata/sata_mv.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index f8c33e3772b8..7fac4d0fee86 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -2423,10 +2423,19 @@ static struct ata_queued_cmd *mv_get_active_qc(struct ata_port *ap)
 {
 	struct mv_port_priv *pp = ap->private_data;
 	struct ata_queued_cmd *qc;
+	struct ata_link *link = NULL;
 
 	if (pp->pp_flags & MV_PP_FLAG_NCQ_EN)
 		return NULL;
-	qc = ata_qc_from_tag(ap, ap->link.active_tag);
+
+	ata_for_each_link(link, ap, EDGE)
+		if (ata_link_active(link))
+			break;
+
+	if (!link)
+		link = &ap->link;
+
+	qc = ata_qc_from_tag(ap, link->active_tag);
 	if (qc && !(qc->tf.flags & ATA_TFLAG_POLLING))
 		return qc;
 	return NULL;
-- 
2.1.0

Re: [PATCH] sata_mv: Manage SATA port multiplier while searching for active links

[Tejun Heo]

Hello,

On Mon, Mar 30, 2015 at 07:32:45PM +0200, Gregory CLEMENT wrote:
> From: Nadav Haklai <nadavh@marvell.com>
> 
> With this patch, when searching for active link, first search through
> the port multiplier links. And then fall to the default ap active_tag
> only if no there is no active link in the port multiplier.

What does this fix?  What was broken before?  What's the impact of the
patch?  A patch description which just restates the patch content
isn't all that useful.

Thanks.

-- 
tejun

Re: [PATCH] sata_mv: Manage SATA port multiplier while searching for active links

[Gregory CLEMENT]

Hi Tejun,

On 30/03/2015 19:35, Tejun Heo wrote:
> Hello,
> 
> On Mon, Mar 30, 2015 at 07:32:45PM +0200, Gregory CLEMENT wrote:
>> From: Nadav Haklai <nadavh@marvell.com>
>>
>> With this patch, when searching for active link, first search through
>> the port multiplier links. And then fall to the default ap active_tag
>> only if no there is no active link in the port multiplier.
> 
> What does this fix?  What was broken before?  What's the impact of the
> patch?  A patch description which just restates the patch content
> isn't all that useful.

I _thought_ that the purpose of this patch was to manage the port multiplier,
and without this patch we don't only handle it. I will ask more detail and
come back with a new version of the patch with a more useful description.

Thanks,

Gregory



> 
> Thanks.
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com