Add new functions ahci_rpm_get_port()/ahci_rpm_put_port() that change
runtime PM status of AHCI ports. Depending if the AHCI host has runtime PM
enabled or disabled calling these may trigger runtime suspend/resume of the
host controller.
We also call these functions in appropriate places to make sure host
controller registers are available before using them.
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/ata/libahci.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 47 insertions(+), 1 deletion(-)
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 2ce4c638714e..a5dc80810a5e 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -224,6 +224,31 @@ static void ahci_enable_ahci(void __iomem *mmio)
WARN_ON(1);
}
+/**
+ * ahci_rpm_get_port - Make sure the port is powered on
+ * @ap: Port to power on
+ *
+ * Whenever there is need to access the AHCI host registers outside of
+ * normal execution paths, call this function to make sure the host is
+ * actually powered on.
+ */
+static int ahci_rpm_get_port(struct ata_port *ap)
+{
+ return pm_runtime_get_sync(ap->dev);
+}
+
+/**
+ * ahci_rpm_put_port - Undoes ahci_rpm_get_port()
+ * @ap: Port to power down
+ *
+ * Undoes ahci_rpm_get_port() and possibly powers down the AHCI host
+ * if it has no more active users.
+ */
+static void ahci_rpm_put_port(struct ata_port *ap)
+{
+ pm_runtime_put(ap->dev);
+}
+
static ssize_t ahci_show_host_caps(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -260,8 +285,13 @@ static ssize_t ahci_show_port_cmd(struct device *dev,
struct Scsi_Host *shost = class_to_shost(dev);
struct ata_port *ap = ata_shost_to_port(shost);
void __iomem *port_mmio = ahci_port_base(ap);
+ ssize_t ret;
- return sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));
+ ahci_rpm_get_port(ap);
+ ret = sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));
+ ahci_rpm_put_port(ap);
+
+ return ret;
}
static ssize_t ahci_read_em_buffer(struct device *dev,
@@ -277,17 +307,20 @@ static ssize_t ahci_read_em_buffer(struct device *dev,
size_t count;
int i;
+ ahci_rpm_get_port(ap);
spin_lock_irqsave(ap->lock, flags);
em_ctl = readl(mmio + HOST_EM_CTL);
if (!(ap->flags & ATA_FLAG_EM) || em_ctl & EM_CTL_XMT ||
!(hpriv->em_msg_type & EM_MSG_TYPE_SGPIO)) {
spin_unlock_irqrestore(ap->lock, flags);
+ ahci_rpm_put_port(ap);
return -EINVAL;
}
if (!(em_ctl & EM_CTL_MR)) {
spin_unlock_irqrestore(ap->lock, flags);
+ ahci_rpm_put_port(ap);
return -EAGAIN;
}
@@ -315,6 +348,7 @@ static ssize_t ahci_read_em_buffer(struct device *dev,
}
spin_unlock_irqrestore(ap->lock, flags);
+ ahci_rpm_put_port(ap);
return i;
}
@@ -339,11 +373,13 @@ static ssize_t ahci_store_em_buffer(struct device *dev,
size % 4 || size > hpriv->em_buf_sz)
return -EINVAL;
+ ahci_rpm_get_port(ap);
spin_lock_irqsave(ap->lock, flags);
em_ctl = readl(mmio + HOST_EM_CTL);
if (em_ctl & EM_CTL_TM) {
spin_unlock_irqrestore(ap->lock, flags);
+ ahci_rpm_put_port(ap);
return -EBUSY;
}
@@ -356,6 +392,7 @@ static ssize_t ahci_store_em_buffer(struct device *dev,
writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
spin_unlock_irqrestore(ap->lock, flags);
+ ahci_rpm_put_port(ap);
return size;
}
@@ -369,7 +406,9 @@ static ssize_t ahci_show_em_supported(struct device *dev,
void __iomem *mmio = hpriv->mmio;
u32 em_ctl;
+ ahci_rpm_get_port(ap);
em_ctl = readl(mmio + HOST_EM_CTL);
+ ahci_rpm_put_port(ap);
return sprintf(buf, "%s%s%s%s\n",
em_ctl & EM_CTL_LED ? "led " : "",
@@ -1010,6 +1049,7 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
else
return -EINVAL;
+ ahci_rpm_get_port(ap);
spin_lock_irqsave(ap->lock, flags);
/*
@@ -1019,6 +1059,7 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
em_ctl = readl(mmio + HOST_EM_CTL);
if (em_ctl & EM_CTL_TM) {
spin_unlock_irqrestore(ap->lock, flags);
+ ahci_rpm_put_port(ap);
return -EBUSY;
}
@@ -1046,6 +1087,8 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
emp->led_state = state;
spin_unlock_irqrestore(ap->lock, flags);
+ ahci_rpm_put_port(ap);
+
return size;
}
@@ -2248,6 +2291,8 @@ static void ahci_pmp_detach(struct ata_port *ap)
int ahci_port_resume(struct ata_port *ap)
{
+ ahci_rpm_get_port(ap);
+
ahci_power_up(ap);
ahci_start_port(ap);
@@ -2274,6 +2319,7 @@ static int ahci_port_suspend(struct ata_port *ap, pm_message_t mesg)
ata_port_freeze(ap);
}
+ ahci_rpm_put_port(ap);
return rc;
}
#endif
--
2.7.0
--
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