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authorTejun Heo <tj@kernel.org>2014-01-16 09:47:17 -0500
committerTejun Heo <tj@kernel.org>2014-01-16 09:49:10 -0500
commitecd75ad514d73efc1bbcc5f10a13566c3ace5f53 (patch)
tree1b391d57f21f809ce35043106a2dc288c8a6bca0 /drivers/ata/libata-scsi.c
parent6e1af69780a4df749d28a129596ed576a0d7996c (diff)
downloadlinux-ecd75ad514d73efc1bbcc5f10a13566c3ace5f53.tar.bz2
libata: disable LPM for some WD SATA-I devices
For some reason, some early WD drives spin up and down drives erratically when the link is put into slumber mode which can reduce the life expectancy of the device significantly. Unfortunately, we don't have full list of devices and given the nature of the issue it'd be better to err on the side of false positives than the other way around. Let's disable LPM on all WD devices which match one of the known problematic model prefixes and are SATA-I. As horkage list doesn't support matching SATA capabilities, this is implemented as two horkages - WD_BROKEN_LPM and NOLPM. The former is set for the known prefixes and sets the latter if the matched device is SATA-I. Note that this isn't optimal as this disables all LPM operations and partial link power state reportedly works fine on these; however, the way LPM is implemented in libata makes it difficult to precisely map libata LPM setting to specific link power state. Well, these devices are already fairly outdated. Let's just disable whole LPM for now. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Nikos Barkas <levelwol@gmail.com> Reported-and-tested-by: Ioannis Barkas <risc4all@yahoo.com> References: https://bugzilla.kernel.org/show_bug.cgi?id=57211 Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/ata/libata-scsi.c')
-rw-r--r--drivers/ata/libata-scsi.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 176f62950e3d..75ef9527603e 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -111,12 +111,14 @@ static const char *ata_lpm_policy_names[] = {
[ATA_LPM_MIN_POWER] = "min_power",
};
-static ssize_t ata_scsi_lpm_store(struct device *dev,
+static ssize_t ata_scsi_lpm_store(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
- struct Scsi_Host *shost = class_to_shost(dev);
+ struct Scsi_Host *shost = class_to_shost(device);
struct ata_port *ap = ata_shost_to_port(shost);
+ struct ata_link *link;
+ struct ata_device *dev;
enum ata_lpm_policy policy;
unsigned long flags;
@@ -132,10 +134,20 @@ static ssize_t ata_scsi_lpm_store(struct device *dev,
return -EINVAL;
spin_lock_irqsave(ap->lock, flags);
+
+ ata_for_each_link(link, ap, EDGE) {
+ ata_for_each_dev(dev, &ap->link, ENABLED) {
+ if (dev->horkage & ATA_HORKAGE_NOLPM) {
+ count = -EOPNOTSUPP;
+ goto out_unlock;
+ }
+ }
+ }
+
ap->target_lpm_policy = policy;
ata_port_schedule_eh(ap);
+out_unlock:
spin_unlock_irqrestore(ap->lock, flags);
-
return count;
}