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path: root/drivers/ata/libahci.c
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Diffstat (limited to 'drivers/ata/libahci.c')
-rw-r--r--drivers/ata/libahci.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index d61740e78d6d..284a176076f5 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -593,8 +593,22 @@ EXPORT_SYMBOL_GPL(ahci_start_engine);
int ahci_stop_engine(struct ata_port *ap)
{
void __iomem *port_mmio = ahci_port_base(ap);
+ struct ahci_host_priv *hpriv = ap->host->private_data;
u32 tmp;
+ /*
+ * On some controllers, stopping a port's DMA engine while the port
+ * is in ALPM state (partial or slumber) results in failures on
+ * subsequent DMA engine starts. For those controllers, put the
+ * port back in active state before stopping its DMA engine.
+ */
+ if ((hpriv->flags & AHCI_HFLAG_WAKE_BEFORE_STOP) &&
+ (ap->link.lpm_policy > ATA_LPM_MAX_POWER) &&
+ ahci_set_lpm(&ap->link, ATA_LPM_MAX_POWER, ATA_LPM_WAKE_ONLY)) {
+ dev_err(ap->host->dev, "Failed to wake up port before engine stop\n");
+ return -EIO;
+ }
+
tmp = readl(port_mmio + PORT_CMD);
/* check if the HBA is idle */
@@ -689,6 +703,9 @@ static int ahci_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
void __iomem *port_mmio = ahci_port_base(ap);
if (policy != ATA_LPM_MAX_POWER) {
+ /* wakeup flag only applies to the max power policy */
+ hints &= ~ATA_LPM_WAKE_ONLY;
+
/*
* Disable interrupts on Phy Ready. This keeps us from
* getting woken up due to spurious phy ready
@@ -704,7 +721,8 @@ static int ahci_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
u32 cmd = readl(port_mmio + PORT_CMD);
if (policy == ATA_LPM_MAX_POWER || !(hints & ATA_LPM_HIPM)) {
- cmd &= ~(PORT_CMD_ASP | PORT_CMD_ALPE);
+ if (!(hints & ATA_LPM_WAKE_ONLY))
+ cmd &= ~(PORT_CMD_ASP | PORT_CMD_ALPE);
cmd |= PORT_CMD_ICC_ACTIVE;
writel(cmd, port_mmio + PORT_CMD);
@@ -712,6 +730,9 @@ static int ahci_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
/* wait 10ms to be sure we've come out of LPM state */
ata_msleep(ap, 10);
+
+ if (hints & ATA_LPM_WAKE_ONLY)
+ return 0;
} else {
cmd |= PORT_CMD_ALPE;
if (policy == ATA_LPM_MIN_POWER)