linux/include
Lukas Wunner 1758bde2e4 net: phy: Don't trigger state machine while in suspend
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 1ce8b37241 ("usbnet: smsc95xx: Forward
PHY interrupts to PHY driver to avoid polling"), but has existed since
forever.

Fixes: 541cd3ee00 ("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>
2022-06-29 20:38:52 -07:00
..
acpi cxl for 5.19 2022-05-27 21:24:19 -07:00
asm-generic kernel: add platform_has() infrastructure 2022-06-06 08:06:00 +02:00
clocksource pwm: Changes for v5.19-rc1 2022-06-01 10:49:11 -07:00
crypto
drm drm/ttm: fix bulk move handling v2 2022-06-14 11:15:19 +02:00
dt-bindings Char / Misc / Other smaller driver subsystem updates for 5.19-rc1 2022-06-03 11:36:34 -07:00
keys certs: Move load_certificate_list() to be with the asymmetric keys code 2022-06-21 16:05:06 +01:00
kunit kunit: take kunit_assert as const 2022-05-16 13:23:00 -06:00
kvm Merge branch kvm-arm64/per-vcpu-host-pmu-data into kvmarm-master/next 2022-05-16 17:48:36 +01:00
linux net: phy: Don't trigger state machine while in suspend 2022-06-29 20:38:52 -07:00
math-emu
media media: h264: Sort p/b reflist using frame_num 2022-05-17 10:02:29 +02:00
memory
misc
net netfilter: nf_tables: avoid skb access on nf_stolen 2022-06-27 19:22:54 +02:00
pcmcia
ras
rdma RDMA/core: Fix typo in comment 2022-05-24 11:24:58 -03:00
scsi SCSI misc on 20220524 2022-05-25 19:09:48 -07:00
soc ARM: driver changes for 5.19 2022-05-26 10:32:47 -07:00
sound ARM: multiplatform changes, part 2 2022-06-02 15:23:54 -07:00
target SCSI misc on 20220524 2022-05-25 19:09:48 -07:00
trace workqueue: Fix type of cpu in trace event 2022-06-07 07:09:47 -10:00
uapi mptcp: fix conflict with <netinet/in.h> 2022-06-28 20:45:43 -07:00
ufs scsi: ufs: Split the drivers/scsi/ufs directory 2022-05-19 20:27:37 -04:00
vdso
video video: fbdev: radeon: Fix spelling typo in comment 2022-05-26 13:38:59 +02:00
xen arm/xen: Assign xen-grant DMA ops for xen-grant DMA devices 2022-06-06 16:07:30 +02:00