[PATCH v2 2/6] driver core: Set deferred probe reason when deferred by driver core

Saravana Kannan
2021-09-15T08:12:13Z

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.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
drivers/base/core.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 316df6027093..ca6c61a2e2e9 100644
--- 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;
}
--
2.33.0.309.g3052b89438-goog