firmware: arm_scmi: Clear SystemPower flag on create failure

__scmi_device_create() reserves the singleton SystemPower protocol device
before registering the SCMI device. If any later step fails, a stale
reservation can make a later retry reject SystemPower device creation
permanently, for example after probe deferral.

A plain global boolean is not enough to track the reservation. A delayed
final release of an older SystemPower device could clear the boolean after
a newer device has already claimed it, breaking the singleton guarantee for
the active device.

Track the reservation with the scmi_device pointer itself. Claim it with
cmpxchg(NULL, scmi_dev) after allocating the device object, and release it
with cmpxchg(scmi_dev, NULL) from the common cleanup helper. This lets the
create-failure, explicit destroy and final release paths clear only the
reservation owned by the device being cleaned up.

Fixes: 2c3e674465e7 ("firmware: arm_scmi: Refactor device create/destroy helpers")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Link: https://patch.msgid.link/20260714-scmi_core_fixes-v6-11-3afe499d46e3@kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>

0 files changed, 0 insertions, 0 deletions