driver core: Set deferred probe reason when deferred by driver core

When the driver core defers the probe of a device, set the deferred
probe reason so that it's easier to debug. The deferred probe reason is
available in debugfs under devices_deferred.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210915172808.620546-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 21d4cb5..bf00804 100644 (file)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -975,6 +975,7 @@ int device_links_check_suppliers(struct device *dev)
 {
        struct device_link *link;
        int ret = 0;
+       struct fwnode_handle *sup_fw;
 
        /*
         * Device waiting for supplier to become available is not allowed to
@@ -983,10 +984,11 @@ int device_links_check_suppliers(struct device *dev)
        mutex_lock(&fwnode_link_lock);
        if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
            !fw_devlink_is_permissive()) {
-               dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
-                       list_first_entry(&dev->fwnode->suppliers,
-                       struct fwnode_link,
-                       c_hook)->supplier);
+               sup_fw = list_first_entry(&dev->fwnode->suppliers,
+                                         struct fwnode_link,
+                                         c_hook)->supplier;
+               dev_err_probe(dev, -EPROBE_DEFER, "wait for supplier %pfwP\n",
+                             sup_fw);
                mutex_unlock(&fwnode_link_lock);
                return -EPROBE_DEFER;
        }
@@ -1001,8 +1003,9 @@ int device_links_check_suppliers(struct device *dev)
                if (link->status != DL_STATE_AVAILABLE &&
                    !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
                        device_links_missing_supplier(dev);
-                       dev_dbg(dev, "probe deferral - supplier %s not ready\n",
-                               dev_name(link->supplier));
+                       dev_err_probe(dev, -EPROBE_DEFER,
+                                     "supplier %s not ready\n",
+                                     dev_name(link->supplier));
                        ret = -EPROBE_DEFER;
                        break;
                }