[PATCH 5.15 119/136] Revert "usbnet: smsc95xx: Fix deadlock on runtime resume"

Greg Kroah-Hartman
2022-08-29T11:31:17Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit b574d1e3e9a2432b5acd9c4a9dc8d70b6a37aaf1 which is
commit 7b960c967f2aa01ab8f45c5a0bd78e754cffdeee upstream.

It is reported to cause problems, so drop it from the 5.15.y tree until
the root cause can be determined.

Reported-by: Lukas Wunner <lukas@wunner.de>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Ferry Toth <fntoth@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andre Edich <andre.edich@microchip.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Sasha Levin <sashal@kernel.org>
Link: https://lore.kernel.org/r/20220826132137.GA24932@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/usb/smsc95xx.c | 26 ++++++--------------------
1 file changed, 6 insertions(+), 20 deletions(-)

--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -69,7 +69,6 @@ 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;
@@ -79,14 +78,13 @@ MODULE_PARM_DESC(turbo_mode, "Enable mul
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 (current != pdata->pm_task)
+ if (!in_pm)
fn = usbnet_read_cmd;
else
fn = usbnet_read_cmd_nopm;
@@ -110,14 +108,13 @@ static int __must_check __smsc95xx_read_
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 (current != pdata->pm_task)
+ if (!in_pm)
fn = usbnet_write_cmd;
else
fn = usbnet_write_cmd_nopm;
@@ -1485,12 +1482,9 @@ static int smsc95xx_suspend(struct usb_i
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;
}

@@ -1730,7 +1724,6 @@ done:
if (ret && PMSG_IS_AUTO(message))
usbnet_resume(intf);

- pdata->pm_task = NULL;
return ret;
}

@@ -1751,31 +1744,29 @@ static int smsc95xx_resume(struct usb_in
/* 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)
- goto done;
+ return ret;

val &= ~(WUCSR_WAKE_EN_ | WUCSR_MPEN_);

ret = smsc95xx_write_reg_nopm(dev, WUCSR, val);
if (ret < 0)
- goto done;
+ return ret;

/* clear wake-up status */
ret = smsc95xx_read_reg_nopm(dev, PM_CTRL, &val);
if (ret < 0)
- goto done;
+ return ret;

val &= ~PM_CTL_WOL_EN_;
val |= PM_CTL_WUPS_;

ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val);
if (ret < 0)
- goto done;
+ return ret;
}

phy_init_hw(pdata->phydev);
@@ -1784,20 +1775,15 @@ static int smsc95xx_resume(struct usb_in
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;