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Subject[PATCH v1 2/5] driver core: Set deferred probe reason when deferred by driver core
From
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 | 36 +++++++++++++++++++++++++++++++++---
1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 316df6027093..41f456904272 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -955,6 +955,29 @@ static void device_links_missing_supplier(struct device *dev)
}
}

+/**
+ * dev_set_def_probe_reason - Set the deferred probe reason for a device
+ * @dev: the pointer to the struct device
+ * @fmt: printf-style format string
+ * @...: arguments as specified in the format string
+ *
+ * This is a more caller-friendly version of device_set_deferred_probe_reason()
+ * that takes variable argument inputs similar to dev_info().
+ */
+static void dev_set_def_probe_reason(const struct device *dev, const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ device_set_deferred_probe_reason(dev, &vaf);
+
+ va_end(args);
+}
+
/**
* device_links_check_suppliers - Check presence of supplier drivers.
* @dev: Consumer device.
@@ -975,6 +998,7 @@ 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 +1007,13 @@ 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()) {
+ sup_fw = list_first_entry(&dev->fwnode->suppliers,
+ struct fwnode_link,
+ c_hook)->supplier;
dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
- list_first_entry(&dev->fwnode->suppliers,
- struct fwnode_link,
- c_hook)->supplier);
+ sup_fw);
+ dev_set_def_probe_reason(dev,
+ "wait for supplier %pfwP\n", sup_fw);
mutex_unlock(&fwnode_link_lock);
return -EPROBE_DEFER;
}
@@ -1003,6 +1030,9 @@ int device_links_check_suppliers(struct device *dev)
device_links_missing_supplier(dev);
dev_dbg(dev, "probe deferral - supplier %s not ready\n",
dev_name(link->supplier));
+ dev_set_def_probe_reason(dev,
+ "supplier %s not ready\n",
+ dev_name(link->supplier));
ret = -EPROBE_DEFER;
break;
}
--
2.33.0.309.g3052b89438-goog
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