[PATCH] net: stmmac: Use mutex instead of spinlock

From: Thierry Reding
Date: Thu May 24 2018 - 09:16:36 EST


From: Thierry Reding <treding@xxxxxxxxxx>

Some drivers, such as DWC EQOS on Tegra, need to perform operations that
can sleep under this lock (clk_set_rate() in tegra_eqos_fix_speed()) for
proper operation. Since there is no need for this lock to be a spinlock,
convert it to a mutex instead.

Fixes: e6ea2d16fc61 ("net: stmmac: dwc-qos: Add Tegra186 support")
Reported-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
This applies on top of net-next.

drivers/net/ethernet/stmicro/stmmac/stmmac.h | 2 +-
.../ethernet/stmicro/stmmac/stmmac_ethtool.c | 12 +++----
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 31 +++++++++----------
3 files changed, 21 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 42fc76e76bf9..5a2570b8d540 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -121,7 +121,7 @@ struct stmmac_priv {
struct net_device *dev;
struct device *device;
struct mac_device_info *hw;
- spinlock_t lock;
+ struct mutex lock;

/* RX Queue */
struct stmmac_rx_queue rx_queue[MTL_MAX_RX_QUEUES];
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 6d82b3ef5c3b..5710864fa809 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -390,9 +390,9 @@ stmmac_ethtool_set_link_ksettings(struct net_device *dev,
ADVERTISED_10baseT_Half |
ADVERTISED_10baseT_Full);

- spin_lock(&priv->lock);
+ mutex_lock(&priv->lock);
stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 1, priv->hw->ps, 0);
- spin_unlock(&priv->lock);
+ mutex_unlock(&priv->lock);

return 0;
}
@@ -632,12 +632,12 @@ static void stmmac_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
{
struct stmmac_priv *priv = netdev_priv(dev);

- spin_lock_irq(&priv->lock);
+ mutex_lock(&priv->lock);
if (device_can_wakeup(priv->device)) {
wol->supported = WAKE_MAGIC | WAKE_UCAST;
wol->wolopts = priv->wolopts;
}
- spin_unlock_irq(&priv->lock);
+ mutex_unlock(&priv->lock);
}

static int stmmac_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
@@ -666,9 +666,9 @@ static int stmmac_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
disable_irq_wake(priv->wol_irq);
}

- spin_lock_irq(&priv->lock);
+ mutex_lock(&priv->lock);
priv->wolopts = wol->wolopts;
- spin_unlock_irq(&priv->lock);
+ mutex_unlock(&priv->lock);

return 0;
}
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index d9dbe1355896..8cc63da79a80 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -381,7 +381,6 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
{
struct net_device *ndev = priv->dev;
int interface = priv->plat->interface;
- unsigned long flags;
bool ret = false;

if ((interface != PHY_INTERFACE_MODE_MII) &&
@@ -408,7 +407,7 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
* changed).
* In that case the driver disable own timers.
*/
- spin_lock_irqsave(&priv->lock, flags);
+ mutex_lock(&priv->lock);
if (priv->eee_active) {
netdev_dbg(priv->dev, "disable EEE\n");
del_timer_sync(&priv->eee_ctrl_timer);
@@ -416,11 +415,11 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
tx_lpi_timer);
}
priv->eee_active = 0;
- spin_unlock_irqrestore(&priv->lock, flags);
+ mutex_unlock(&priv->lock);
goto out;
}
/* Activate the EEE and start timers */
- spin_lock_irqsave(&priv->lock, flags);
+ mutex_lock(&priv->lock);
if (!priv->eee_active) {
priv->eee_active = 1;
timer_setup(&priv->eee_ctrl_timer,
@@ -435,7 +434,7 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
stmmac_set_eee_pls(priv, priv->hw, ndev->phydev->link);

ret = true;
- spin_unlock_irqrestore(&priv->lock, flags);
+ mutex_unlock(&priv->lock);

netdev_dbg(priv->dev, "Energy-Efficient Ethernet initialized\n");
}
@@ -811,13 +810,12 @@ static void stmmac_adjust_link(struct net_device *dev)
{
struct stmmac_priv *priv = netdev_priv(dev);
struct phy_device *phydev = dev->phydev;
- unsigned long flags;
bool new_state = false;

if (!phydev)
return;

- spin_lock_irqsave(&priv->lock, flags);
+ mutex_lock(&priv->lock);

if (phydev->link) {
u32 ctrl = readl(priv->ioaddr + MAC_CTRL_REG);
@@ -876,7 +874,7 @@ static void stmmac_adjust_link(struct net_device *dev)
if (new_state && netif_msg_link(priv))
phy_print_status(phydev);

- spin_unlock_irqrestore(&priv->lock, flags);
+ mutex_unlock(&priv->lock);

if (phydev->is_pseudo_fixed_link)
/* Stop PHY layer to call the hook to adjust the link in case
@@ -4337,7 +4335,7 @@ int stmmac_dvr_probe(struct device *device,
(8 * priv->plat->rx_queues_to_use));
}

- spin_lock_init(&priv->lock);
+ mutex_init(&priv->lock);

/* If a specific clk_csr value is passed from the platform
* this means that the CSR Clock Range selection cannot be
@@ -4421,6 +4419,7 @@ int stmmac_dvr_remove(struct device *dev)
priv->hw->pcs != STMMAC_PCS_RTBI)
stmmac_mdio_unregister(ndev);
destroy_workqueue(priv->wq);
+ mutex_destroy(&priv->lock);
free_netdev(ndev);

return 0;
@@ -4438,7 +4437,6 @@ int stmmac_suspend(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct stmmac_priv *priv = netdev_priv(ndev);
- unsigned long flags;

if (!ndev || !netif_running(ndev))
return 0;
@@ -4446,7 +4444,7 @@ int stmmac_suspend(struct device *dev)
if (ndev->phydev)
phy_stop(ndev->phydev);

- spin_lock_irqsave(&priv->lock, flags);
+ mutex_lock(&priv->lock);

netif_device_detach(ndev);
stmmac_stop_all_queues(priv);
@@ -4467,7 +4465,7 @@ int stmmac_suspend(struct device *dev)
clk_disable(priv->plat->pclk);
clk_disable(priv->plat->stmmac_clk);
}
- spin_unlock_irqrestore(&priv->lock, flags);
+ mutex_unlock(&priv->lock);

priv->oldlink = false;
priv->speed = SPEED_UNKNOWN;
@@ -4512,7 +4510,6 @@ int stmmac_resume(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct stmmac_priv *priv = netdev_priv(ndev);
- unsigned long flags;

if (!netif_running(ndev))
return 0;
@@ -4524,9 +4521,9 @@ int stmmac_resume(struct device *dev)
* from another devices (e.g. serial console).
*/
if (device_may_wakeup(priv->device)) {
- spin_lock_irqsave(&priv->lock, flags);
+ mutex_lock(&priv->lock);
stmmac_pmt(priv, priv->hw, 0);
- spin_unlock_irqrestore(&priv->lock, flags);
+ mutex_unlock(&priv->lock);
priv->irq_wake = 0;
} else {
pinctrl_pm_select_default_state(priv->device);
@@ -4540,7 +4537,7 @@ int stmmac_resume(struct device *dev)

netif_device_attach(ndev);

- spin_lock_irqsave(&priv->lock, flags);
+ mutex_lock(&priv->lock);

stmmac_reset_queues_param(priv);

@@ -4554,7 +4551,7 @@ int stmmac_resume(struct device *dev)

stmmac_start_all_queues(priv);

- spin_unlock_irqrestore(&priv->lock, flags);
+ mutex_unlock(&priv->lock);

if (ndev->phydev)
phy_start(ndev->phydev);
--
2.17.0