Revision 1758bde2e4aa5ff188d53e7d9d388bbb7e12eebb authored by Lukas Wunner on 28 June 2022, 10:15:08 UTC, committed by Jakub Kicinski on 30 June 2022, 03:38:52 UTC
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 1ce8b37241ed ("usbnet: smsc95xx: Forward PHY interrupts to PHY driver to avoid polling"), but has existed since forever. Fixes: 541cd3ee00a4 ("phylib: Fix deadlock on resume") 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 # v2.6.33+ Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/b7f386d04e9b5b0e2738f0125743e30676f309ef.1656410895.git.lukas@wunner.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent e65af54
File | Mode | Size |
---|---|---|
Design | ||
NMI-RCU.rst | -rw-r--r-- | 4.2 KB |
RTFP.txt | -rw-r--r-- | 84.2 KB |
UP.rst | -rw-r--r-- | 5.8 KB |
arrayRCU.rst | -rw-r--r-- | 5.5 KB |
checklist.rst | -rw-r--r-- | 22.6 KB |
index.rst | -rw-r--r-- | 575 bytes |
listRCU.rst | -rw-r--r-- | 16.3 KB |
lockdep-splat.rst | -rw-r--r-- | 5.0 KB |
lockdep.rst | -rw-r--r-- | 5.0 KB |
rcu.rst | -rw-r--r-- | 3.7 KB |
rcu_dereference.rst | -rw-r--r-- | 16.6 KB |
rcubarrier.rst | -rw-r--r-- | 13.3 KB |
rculist_nulls.rst | -rw-r--r-- | 5.5 KB |
rcuref.rst | -rw-r--r-- | 5.2 KB |
stallwarn.rst | -rw-r--r-- | 18.0 KB |
torture.rst | -rw-r--r-- | 13.5 KB |
whatisRCU.rst | -rw-r--r-- | 45.5 KB |
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...