@@ -71,6 +71,7 @@ struct smsc95xx_priv {
struct fwnode_handle *irqfwnode;
struct mii_bus *mdiobus;
struct phy_device *phydev;
+ struct task_struct *pm_task;
};
static bool turbo_mode = true;
@@ -80,13 +81,14 @@ MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");
static int __must_check __smsc95xx_read_reg(struct usbnet *dev, u32 index,
u32 *data, int in_pm)
{
+ struct smsc95xx_priv *pdata = dev->driver_priv;
u32 buf;
int ret;
int (*fn)(struct usbnet *, u8, u8, u16, u16, void *, u16);
BUG_ON(!dev);
- if (!in_pm)
+ if (current != pdata->pm_task)
fn = usbnet_read_cmd;
else
fn = usbnet_read_cmd_nopm;
@@ -110,13 +112,14 @@ static int __must_check __smsc95xx_read_reg(struct usbnet *dev, u32 index,
static int __must_check __smsc95xx_write_reg(struct usbnet *dev, u32 index,
u32 data, int in_pm)
{
+ struct smsc95xx_priv *pdata = dev->driver_priv;
u32 buf;
int ret;
int (*fn)(struct usbnet *, u8, u8, u16, u16, const void *, u16);
BUG_ON(!dev);
- if (!in_pm)
+ if (current != pdata->pm_task)
fn = usbnet_write_cmd;
else
fn = usbnet_write_cmd_nopm;
@@ -1490,9 +1493,12 @@ static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message)
u32 val, link_up;
int ret;
+ pdata->pm_task = current;
+
ret = usbnet_suspend(intf, message);
if (ret < 0) {
netdev_warn(dev->net, "usbnet_suspend error\n");
+ pdata->pm_task = NULL;
return ret;
}
@@ -1732,6 +1738,7 @@ static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message)
if (ret && PMSG_IS_AUTO(message))
usbnet_resume(intf);
+ pdata->pm_task = NULL;
return ret;
}
@@ -1752,29 +1759,31 @@ static int smsc95xx_resume(struct usb_interface *intf)
/* do this first to ensure it's cleared even in error case */
pdata->suspend_flags = 0;
+ pdata->pm_task = current;
+
if (suspend_flags & SUSPEND_ALLMODES) {
/* clear wake-up sources */
ret = smsc95xx_read_reg_nopm(dev, WUCSR, &val);
if (ret < 0)
- return ret;
+ goto done;
val &= ~(WUCSR_WAKE_EN_ | WUCSR_MPEN_);
ret = smsc95xx_write_reg_nopm(dev, WUCSR, val);
if (ret < 0)
- return ret;
+ goto done;
/* clear wake-up status */
ret = smsc95xx_read_reg_nopm(dev, PM_CTRL, &val);
if (ret < 0)
- return ret;
+ goto done;
val &= ~PM_CTL_WOL_EN_;
val |= PM_CTL_WUPS_;
ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val);
if (ret < 0)
- return ret;
+ goto done;
}
phy_init_hw(pdata->phydev);
@@ -1783,15 +1792,20 @@ static int smsc95xx_resume(struct usb_interface *intf)
if (ret < 0)
netdev_warn(dev->net, "usbnet_resume error\n");
+done:
+ pdata->pm_task = NULL;
return ret;
}
static int smsc95xx_reset_resume(struct usb_interface *intf)
{
struct usbnet *dev = usb_get_intfdata(intf);
+ struct smsc95xx_priv *pdata = dev->driver_priv;
int ret;
+ pdata->pm_task = current;
ret = smsc95xx_reset(dev);
+ pdata->pm_task = NULL;
if (ret < 0)
return ret;
Commit 05b35e7eb9a1 ("smsc95xx: add phylib support") amended smsc95xx_resume() to call phy_init_hw(). That function waits for the device to runtime resume even though it is placed in the runtime resume path, causing a deadlock. The problem is that phy_init_hw() calls down to smsc95xx_mdiobus_read(), which never uses the _nopm variant of usbnet_read_cmd(). Commit b4df480f68ae ("usbnet: smsc95xx: add reset_resume function with reset operation") causes a similar deadlock on resume if the device was already runtime suspended when entering system sleep: That's because the commit introduced smsc95xx_reset_resume(), which calls down to smsc95xx_reset(), which neglects to use _nopm accessors. Fix by auto-detecting whether a device access is performed by the suspend/resume task_struct and use the _nopm variant if so. This works because the PM core guarantees that suspend/resume callbacks are run in task context. Stacktrace for posterity: INFO: task kworker/2:1:49 blocked for more than 122 seconds. Workqueue: usb_hub_wq hub_event schedule rpm_resume __pm_runtime_resume usb_autopm_get_interface usbnet_read_cmd __smsc95xx_read_reg __smsc95xx_phy_wait_not_busy __smsc95xx_mdio_read smsc95xx_mdiobus_read __mdiobus_read mdiobus_read smsc_phy_reset phy_init_hw smsc95xx_resume usb_resume_interface usb_resume_both usb_runtime_resume __rpm_callback rpm_callback rpm_resume __pm_runtime_resume usb_autoresume_device hub_event process_one_work Fixes: b4df480f68ae ("usbnet: smsc95xx: add reset_resume function with reset operation") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v3.16+ Cc: Andre Edich <andre.edich@microchip.com> --- drivers/net/usb/smsc95xx.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-)