[patch 10/50] libata: force hardreset if link is in powersave mode

[patch 10/50] libata: force hardreset if link is in powersave mode

[Chris Wright]

[-- Attachment #1: libata-force-hardreset-if-link-is-in-powersave-mode.patch --]
[-- Type: text/plain, Size: 1533 bytes --]

-stable review patch.  If anyone has any objections, please let us know.
---------------------

From: Tejun Heo <htejun@gmail.com>

Inhibiting link PM mode doesn't bring the link back online if it's
already in powersave mode.  If SRST is used in these cases, libata EH
thinks that the link is offline and fails detection.  Force hardreset
if link is in powersave mode.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

---
 drivers/ata/libata-core.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3947,6 +3947,7 @@ int ata_std_prereset(struct ata_link *li
 	struct ata_port *ap = link->ap;
 	struct ata_eh_context *ehc = &link->eh_context;
 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
+	u32 sstatus;
 	int rc;
 
 	/* handle link resume */
@@ -3960,6 +3961,17 @@ int ata_std_prereset(struct ata_link *li
 	if (ap->flags & ATA_FLAG_PMP)
 		ehc->i.action |= ATA_EH_HARDRESET;
 
+	/* if link powersave is on, force hardreset */
+	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0) {
+		u8 ipm = sstatus >> 8;
+
+		if (ipm == 2 || ipm == 6) {
+			ata_link_printk(link, KERN_INFO, "link in powersave "
+				"mode (ipm=%d), forcing hardreset\n", ipm);
+			ehc->i.action |= ATA_EH_HARDRESET;
+		}
+	}
+
 	/* if we're about to do hardreset, nothing more to do */
 	if (ehc->i.action & ATA_EH_HARDRESET)
 		return 0;

-- 

Re: [patch 10/50] libata: force hardreset if link is in powersave mode

[Linus Torvalds]

On Fri, 6 Jun 2008, Chris Wright wrote:
>
> -stable review patch.  If anyone has any objections, please let us know.
> ---------------------
> 
> From: Tejun Heo <htejun@gmail.com>
> 
> Inhibiting link PM mode doesn't bring the link back online if it's
> already in powersave mode.  If SRST is used in these cases, libata EH
> thinks that the link is offline and fails detection.  Force hardreset
> if link is in powersave mode.

This isn't upstream. Maybe there's some reason it's not needed upstream, 
but it would be nice to know.

		Linus

Re: [stable] [patch 10/50] libata: force hardreset if link is in powersave mode

[Greg KH]

On Fri, Jun 06, 2008 at 06:27:15PM -0700, Linus Torvalds wrote:
> 
> 
> On Fri, 6 Jun 2008, Chris Wright wrote:
> >
> > -stable review patch.  If anyone has any objections, please let us know.
> > ---------------------
> > 
> > From: Tejun Heo <htejun@gmail.com>
> > 
> > Inhibiting link PM mode doesn't bring the link back online if it's
> > already in powersave mode.  If SRST is used in these cases, libata EH
> > thinks that the link is offline and fails detection.  Force hardreset
> > if link is in powersave mode.
> 
> This isn't upstream. Maybe there's some reason it's not needed upstream, 
> but it would be nice to know.

To quote Tejun when he sent this patch:
	---
	Patch for -stable only.  Devel branch now uses hardreset by
	default so this type of promotion logic isn't necessary anymore.


thanks,

greg k-h

Re: [stable] [patch 10/50] libata: force hardreset if link is in powersave mode

[Linus Torvalds]

On Fri, 6 Jun 2008, Greg KH wrote:
> > 
> > This isn't upstream. Maybe there's some reason it's not needed upstream, 
> > but it would be nice to know.
> 
> To quote Tejun when he sent this patch:
> 	---
> 	Patch for -stable only.  Devel branch now uses hardreset by
> 	default so this type of promotion logic isn't necessary anymore.

Ok, thanks,

		Linus

Re: [patch 10/50] libata: force hardreset if link is in powersave mode

[Jeff Garzik]

Linus Torvalds wrote:
> 
> On Fri, 6 Jun 2008, Chris Wright wrote:
>> -stable review patch.  If anyone has any objections, please let us know.
>> ---------------------
>>
>> From: Tejun Heo <htejun@gmail.com>
>>
>> Inhibiting link PM mode doesn't bring the link back online if it's
>> already in powersave mode.  If SRST is used in these cases, libata EH
>> thinks that the link is offline and fails detection.  Force hardreset
>> if link is in powersave mode.
> 
> This isn't upstream. Maybe there's some reason it's not needed upstream, 
> but it would be nice to know.

We do hard reset by default...

	Jeff