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Mika Westerberg c1976a4248 thunderbolt: Runtime PM activate both ends of the device link
[ Upstream commit f3380cac0c0b3a6f49ab161e2a057c363962f48d ]

If protocol tunnels are already up when the driver is loaded, for
instance if the boot firmware implements connection manager of its own,
runtime PM reference count of the consumer devices behind the tunnel
might have been increased already before the device link is created but
the supplier device runtime PM reference count is not. This leads to a
situation where the supplier (the Thunderbolt driver) can runtime
suspend even if it should not because the corresponding protocol tunnel
needs to be up causing the devices to be removed from the corresponding
native bus.

Prevent this from happening by making both sides of the link runtime PM
active briefly. The pm_runtime_put() for the consumer (PCIe
root/downstream port, xHCI) then allows it to runtime suspend again but
keeps the supplier runtime resumed the whole time it is runtime active.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 10:54:14 +01:00
arch x86/mm: Flush global TLB when switching to trampoline page-table 2022-01-27 10:54:14 +01:00
block
certs
crypto crypto: jitter - consider 32 LSB for APT 2022-01-27 10:54:12 +01:00
Documentation
drivers thunderbolt: Runtime PM activate both ends of the device link 2022-01-27 10:54:14 +01:00
fs
include ACPI: Change acpi_device_always_present() into acpi_device_override_status() 2022-01-27 10:54:13 +01:00
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