[04/99] libata: fix PMP initialization

From: Greg KH
Date: Fri Nov 06 2009 - 17:48:33 EST

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

From: Tejun Heo <tj@xxxxxxxxxx>

commit 4f7c2874995ac48a4622755b8bd159eb2fb6d8f4 upstream.

Commit 842faa6c1a1d6faddf3377948e5cf214812c6c90 fixed error handling
during attach by not committing detected device class to dev->class
while attaching a new device. However, this change missed the PMP
class check in the configuration loop causing a new PMP device to go
through ata_dev_configure() as if it were an ATA or ATAPI device.

As PMP device doesn't have a regular IDENTIFY data, this makes
ata_dev_configure() tries to configure a PMP device using an invalid
data. For the most part, it wasn't too harmful and went unnoticed but
this ends up clearing dev->flags which may have ATA_DFLAG_AN set by
sata_pmp_attach(). This means that SATA_PMP_FEAT_NOTIFY ends up being
disabled on PMPs and on PMPs which honor the flag breaks hotplug

This problem was discovered and reported by Ethan Hsiao.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Reported-by: Ethan Hsiao <ethanhsiao@xxxxxxxxxxx>
Signed-off-by: Jeff Garzik <jgarzik@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

drivers/ata/libata-eh.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2849,12 +2849,14 @@ static int ata_eh_revalidate_and_attach(
* device detection messages backwards.
ata_for_each_dev(dev, link, ALL) {
- if (!(new_mask & (1 << dev->devno)) ||
- dev->class == ATA_DEV_PMP)
+ if (!(new_mask & (1 << dev->devno)))

dev->class = ehc->classes[dev->devno];

+ if (dev->class == ATA_DEV_PMP)
+ continue;
ehc->i.flags |= ATA_EHI_PRINTINFO;
rc = ata_dev_configure(dev);
ehc->i.flags &= ~ATA_EHI_PRINTINFO;

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