From: Saravana Kannan <saravanak@google.com>
Date: Mon, 6 Feb 2023 17:41:54 -0800
Subject: [PATCH] driver core: fw_devlink: Improve check for fwnode with no
 device/driver
References: bsc#1012628
Patch-mainline: 6.2.3
Git-commit: 411c0d58ca6faa9bc4b9f5382118a31c7bb92a6f

[ 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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 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 05c3e9a0..8f32e2cb 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
-- 
2.35.3