@@ -31,6 +31,7 @@
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>
+#include <linux/suspend.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/sock.h>
@@ -976,6 +977,28 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
struct phy_driver *drv = phydev->drv;
irqreturn_t ret;
+ /* Wakeup interrupts may occur during a system sleep transition.
+ * Postpone handling until the PHY has resumed.
+ */
+ if (IS_ENABLED(CONFIG_PM_SLEEP) && phydev->irq_suspended) {
+ struct net_device *netdev = phydev->attached_dev;
+
+ if (netdev) {
+ struct device *parent = netdev->dev.parent;
+
+ if (netdev->wol_enabled)
+ pm_system_wakeup();
+ else if (device_may_wakeup(&netdev->dev))
+ pm_wakeup_dev_event(&netdev->dev, 0, true);
+ else if (parent && device_may_wakeup(parent))
+ pm_wakeup_dev_event(parent, 0, true);
+ }
+
+ phydev->irq_rerun = 1;
+ disable_irq_nosync(irq);
+ return IRQ_HANDLED;
+ }
+
mutex_lock(&phydev->lock);
ret = drv->handle_interrupt(phydev);
mutex_unlock(&phydev->lock);
@@ -278,6 +278,15 @@ static __maybe_unused int mdio_bus_phy_suspend(struct device *dev)
if (phydev->mac_managed_pm)
return 0;
+ /* Wakeup interrupts may occur during the system sleep transition when
+ * the PHY is inaccessible. Set flag to postpone handling until the PHY
+ * has resumed. Wait for concurrent interrupt handler to complete.
+ */
+ if (phy_interrupt_is_valid(phydev)) {
+ phydev->irq_suspended = 1;
+ synchronize_irq(phydev->irq);
+ }
+
/* We must stop the state machine manually, otherwise it stops out of
* control, possibly with the phydev->lock held. Upon resume, netdev
* may call phy routines that try to grab the same lock, and that may
@@ -315,6 +324,20 @@ static __maybe_unused int mdio_bus_phy_resume(struct device *dev)
if (ret < 0)
return ret;
no_resume:
+ if (phy_interrupt_is_valid(phydev)) {
+ phydev->irq_suspended = 0;
+ synchronize_irq(phydev->irq);
+
+ /* Rerun interrupts which were postponed by phy_interrupt()
+ * because they occurred during the system sleep transition.
+ */
+ if (phydev->irq_rerun) {
+ phydev->irq_rerun = 0;
+ enable_irq(phydev->irq);
+ irq_wake_thread(phydev->irq, phydev);
+ }
+ }
+
if (phydev->attached_dev && phydev->adjust_link)
phy_start_machine(phydev);
@@ -572,6 +572,10 @@ struct macsec_ops;
* @mdix_ctrl: User setting of crossover
* @pma_extable: Cached value of PMA/PMD Extended Abilities Register
* @interrupts: Flag interrupts have been enabled
+ * @irq_suspended: Flag indicating PHY is suspended and therefore interrupt
+ * handling shall be postponed until PHY has resumed
+ * @irq_rerun: Flag indicating interrupts occurred while PHY was suspended,
+ * requiring a rerun of the interrupt handler after resume
* @interface: enum phy_interface_t value
* @skb: Netlink message for cable diagnostics
* @nest: Netlink nest used for cable diagnostics
@@ -626,6 +630,8 @@ struct phy_device {
/* Interrupts are enabled */
unsigned interrupts:1;
+ unsigned irq_suspended:1;
+ unsigned irq_rerun:1;
enum phy_state state;
Upon system sleep, mdio_bus_phy_suspend() stops the phy_state_machine(), but subsequent interrupts may retrigger it: They may have been left enabled to facilitate wakeup and are not quiesced until the ->suspend_noirq() phase. Unwanted interrupts may hence occur between mdio_bus_phy_suspend() and dpm_suspend_noirq(), as well as between dpm_resume_noirq() and mdio_bus_phy_resume(). Retriggering the phy_state_machine() through an interrupt is not only undesirable for the reason given in mdio_bus_phy_suspend() (freezing it midway with phydev->lock held), but also because the PHY may be inaccessible after it's suspended: Accesses to USB-attached PHYs are blocked once usb_suspend_both() clears the can_submit flag and PHYs on PCI network cards may become inaccessible upon suspend as well. Amend phy_interrupt() to avoid triggering the state machine if the PHY is suspended. Signal wakeup instead if the attached net_device or its parent has been configured as a wakeup source. (Those conditions are identical to mdio_bus_phy_may_suspend().) Postpone handling of the interrupt until the PHY has resumed. Before stopping the phy_state_machine() in mdio_bus_phy_suspend(), wait for a concurrent phy_interrupt() to run to completion. That is necessary because phy_interrupt() may have checked the PHY's suspend status before the system sleep transition commenced and it may thus retrigger the state machine after it was stopped. Likewise, after re-enabling interrupt handling in mdio_bus_phy_resume(), wait for a concurrent phy_interrupt() to complete to ensure that interrupts which it postponed are properly rerun. The issue was exposed by commit 3873b20fd278 ("usbnet: smsc95xx: Forward PHY interrupts to PHY driver to avoid polling"), but has existed since forever. Hence the stable designation. Link: https://lore.kernel.org/netdev/a5315a8a-32c2-962f-f696-de9a26d30091@samsung.com/ Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable@vger.kernel.org --- Resending as requested by Jakub. No code changes since v1. Changes v1 -> v2: * Extend rationale in commit message. * Drop Fixes tag, add Tested-by tag (Marek). Changes v2 -> v3: * Add stable designation. * Add Acked-by tag (Rafael). Link to v1: https://lore.kernel.org/netdev/688f559346ea747d3b47a4d16ef8277e093f9ebe.1653556322.git.lukas@wunner.de/ Link to v2: https://lore.kernel.org/netdev/cover.1654680790.git.lukas@wunner.de/ drivers/net/phy/phy.c | 23 +++++++++++++++++++++++ drivers/net/phy/phy_device.c | 23 +++++++++++++++++++++++ include/linux/phy.h | 6 ++++++ 3 files changed, 52 insertions(+)