[ Upstream commit bac3b10b78 ]
In attempting to optimize fw_devlink runtime, I introduced numerous cycle
detection bugs by foregoing cycle detection logic under specific
conditions. Each fix has further narrowed the conditions for optimization.
It's time to give up on these optimization attempts and just run the cycle
detection logic every time fw_devlink tries to create a device link.
The specific bug report that triggered this fix involved a supplier fwnode
that never gets a device created for it. Instead, the supplier fwnode is
represented by the device that corresponds to an ancestor fwnode.
In this case, fw_devlink didn't do any cycle detection because the cycle
detection logic is only run when a device link is created between the
devices that correspond to the actual consumer and supplier fwnodes.
With this change, fw_devlink will run cycle detection logic even when
creating SYNC_STATE_ONLY proxy device links from a device that is an
ancestor of a consumer fwnode.
Reported-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Closes: https://lore.kernel.org/all/1a1ab663-d068-40fb-8c94-f0715403d276@ideasonboard.com/
Fixes: 6442d79d88 ("driver core: fw_devlink: Improve detection of overlapping cycles")
Cc: stable <stable@kernel.org>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20241030171009.1853340-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
f3ae93e738