On 14/09/2022 17:50, Krishna Chaitanya Chundru wrote:
On 9/9/2022 2:34 PM, Dmitry Baryshkov wrote:
On Fri, 9 Sept 2022 at 11:45, Krishna chaitanya chundru
<quic_krichai@xxxxxxxxxxx> wrote:
Introducing phy power down/up callbacks for allowing to park the
link-state in L1ss without holding any PCIe resources during
system suspend.
Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
drivers/phy/phy-core.c | 30 ++++++++++++++++++++++++++++++
include/linux/phy/phy.h | 20 ++++++++++++++++++++
2 files changed, 50 insertions(+)
diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index d93ddf1..1b0b757 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -441,6 +441,36 @@ int phy_set_speed(struct phy *phy, int speed)
}
EXPORT_SYMBOL_GPL(phy_set_speed);
+int phy_power_down(struct phy *phy)
+{
+ int ret;
+
+ if (!phy || !phy->ops->power_down)
+ return 0;
+
+ mutex_lock(&phy->mutex);
+ ret = phy->ops->power_down(phy);
+ mutex_unlock(&phy->mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(phy_power_down);
+
+int phy_power_up(struct phy *phy)
+{
+ int ret;
+
+ if (!phy || !phy->ops->power_up)
+ return 0;
+
+ mutex_lock(&phy->mutex);
+ ret = phy->ops->power_up(phy);
+ mutex_unlock(&phy->mutex);
+
+ return ret;
+}
As it can be seen from the phy_power_off(), the PHY can be a shared
resource, with the power_count counting the number of users that
requested the PHY to be powered up. By introducing suc calls you break
directly into this by allowing a single user to power down the PHY, no
matter how many other users have requested the PHY to stay alive.
can we use same power_count in this function also here and restrict the
single user to
power down the PHY same like phy_power_off?.
What is the difference between power_off() and power_down()?
--
With best wishes
Dmitry
