In case of a board which uses a shared IRQ we can easily end up with an
IRQ storm after a forced reboot.
For example, a 'reboot -f' will trigger a call to the .shutdown()
callbacks of all devices. Because phylib does not implement that hook,
the PHY is not quiesced, thus it can very well leave its IRQ enabled.
At the next boot, if that IRQ line is found asserted by the first PHY
driver that uses it, but _before_ the driver that is _actually_ keeping
the shared IRQ asserted is probed, the IRQ is not going to be
acknowledged, thus it will keep being fired preventing the boot process
of the kernel to continue. This is even worse when the second PHY driver
is a module.
To fix this, implement the .shutdown() callback and disable the
interrupts if these are used.
Note that we are still susceptible to IRQ storms if the previous kernel
exited with a panic or if the bootloader left the shared IRQ active, but
there is absolutely nothing we can do about these cases.
Cc: Alexandru Ardelean <[email protected]>
Cc: Andre Edich <[email protected]>
Cc: Antoine Tenart <[email protected]>
Cc: Baruch Siach <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dan Murphy <[email protected]>
Cc: Divya Koppera <[email protected]>
Cc: Florian Fainelli <[email protected]>
Cc: Hauke Mehrtens <[email protected]>
Cc: Heiner Kallweit <[email protected]>
Cc: Jerome Brunet <[email protected]>
Cc: Kavya Sree Kotagiri <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Marco Felsch <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Martin Blumenstingl <[email protected]>
Cc: Mathias Kresin <[email protected]>
Cc: Maxim Kochetkov <[email protected]>
Cc: Michael Walle <[email protected]>
Cc: Neil Armstrong <[email protected]>
Cc: Nisar Sayed <[email protected]>
Cc: Oleksij Rempel <[email protected]>
Cc: Philippe Schenker <[email protected]>
Cc: Willy Liu <[email protected]>
Cc: Yuiko Oshino <[email protected]>
Signed-off-by: Ioana Ciornei <[email protected]>
---
drivers/net/phy/phy_device.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 5dab6be6fc38..413a0a2c5d51 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -2947,6 +2947,13 @@ static int phy_remove(struct device *dev)
return 0;
}
+static void phy_shutdown(struct device *dev)
+{
+ struct phy_device *phydev = to_phy_device(dev);
+
+ phy_disable_interrupts(phydev);
+}
+
/**
* phy_driver_register - register a phy_driver with the PHY layer
* @new_driver: new phy_driver to register
@@ -2970,6 +2977,7 @@ int phy_driver_register(struct phy_driver *new_driver, struct module *owner)
new_driver->mdiodrv.driver.bus = &mdio_bus_type;
new_driver->mdiodrv.driver.probe = phy_probe;
new_driver->mdiodrv.driver.remove = phy_remove;
+ new_driver->mdiodrv.driver.shutdown = phy_shutdown;
new_driver->mdiodrv.driver.owner = owner;
new_driver->mdiodrv.driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
--
2.28.0