From: Saravana Kannan saravanak@google.com
[ Upstream commit 411c0d58ca6faa9bc4b9f5382118a31c7bb92a6f ]
fw_devlink shouldn't defer the probe of a device to wait on a supplier that'll never have a struct device or will never be probed by a driver. We currently check if a supplier falls into this category, but don't check its ancestors. We need to check the ancestors too because if the ancestor will never probe, then the supplier will never probe either.
Signed-off-by: Saravana Kannan saravanak@google.com Tested-by: Colin Foster colin.foster@in-advantage.com Tested-by: Sudeep Holla sudeep.holla@arm.com Tested-by: Douglas Anderson dianders@chromium.org Tested-by: Geert Uytterhoeven geert+renesas@glider.be Tested-by: Luca Weiss luca.weiss@fairphone.com # qcom/sm7225-fairphone-fp4 Link: https://lore.kernel.org/r/20230207014207.1678715-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Stable-dep-of: 3fb16866b51d ("driver core: fw_devlink: Make cycle detection more robust") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/core.c | 40 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 38 insertions(+), 2 deletions(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c index 05c3e9a09b323..8f32e2cbcc63a 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1908,6 +1908,35 @@ static int fw_devlink_relax_cycle(struct device *con, void *sup) return ret; }
+static bool fwnode_init_without_drv(struct fwnode_handle *fwnode) +{ + struct device *dev; + bool ret; + + if (!(fwnode->flags & FWNODE_FLAG_INITIALIZED)) + return false; + + dev = get_dev_from_fwnode(fwnode); + ret = !dev || dev->links.status == DL_DEV_NO_DRIVER; + put_device(dev); + + return ret; +} + +static bool fwnode_ancestor_init_without_drv(struct fwnode_handle *fwnode) +{ + struct fwnode_handle *parent; + + fwnode_for_each_parent_node(fwnode, parent) { + if (fwnode_init_without_drv(parent)) { + fwnode_handle_put(parent); + return true; + } + } + + return false; +} + /** * fw_devlink_create_devlink - Create a device link from a consumer to fwnode * @con: consumer device for the device link @@ -1996,9 +2025,16 @@ static int fw_devlink_create_devlink(struct device *con, goto out; }
- /* Supplier that's already initialized without a struct device. */ - if (sup_handle->flags & FWNODE_FLAG_INITIALIZED) + /* + * Supplier or supplier's ancestor already initialized without a struct + * device or being probed by a driver. + */ + if (fwnode_init_without_drv(sup_handle) || + fwnode_ancestor_init_without_drv(sup_handle)) { + dev_dbg(con, "Not linking %pfwP - Might never probe\n", + sup_handle); return -EINVAL; + }
/* * DL_FLAG_SYNC_STATE_ONLY doesn't block probing and supports