As expected, we would need deferred probing sooner or later. This is
a first approach to allow devices to return -EPROBE_DEFER and get
sorted into a list of deferred devices that will be re-probed later.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>
---
Cc: barebox@xxxxxxxxxxxxxxxxxxx
---
drivers/base/driver.c | 42 +++++++++++++++++++++++++++++++++++++++---
include/asm-generic/errno.h | 1 +
2 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 590c97c96424..5eac21f3c950 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -29,6 +29,7 @@
#include <console.h>
#include <linux/ctype.h>
#include <errno.h>
+#include <init.h>
#include <fs.h>
#include <of.h>
#include <linux/list.h>
@@ -43,6 +44,7 @@ LIST_HEAD(driver_list);
EXPORT_SYMBOL(driver_list);
static LIST_HEAD(active);
+static LIST_HEAD(deferred);
struct device_d *get_device_by_name(const char *name)
{
@@ -88,13 +90,20 @@ int device_probe(struct device_d *dev)
list_add(&dev->active, &active);
ret = dev->bus->probe(dev);
- if (ret) {
+ if (ret == 0)
+ return 0;
+
+ if (ret == -EPROBE_DEFER) {
list_del(&dev->active);
- dev_err(dev, "probe failed: %s\n", strerror(-ret));
+ list_add(&dev->active, &deferred);
+ dev_dbg(dev, "probe deferred\n");
return ret;
}
- return 0;
+ list_del(&dev->active);
+ dev_err(dev, "probe failed: %s\n", strerror(-ret));
+
+ return ret;
}
int device_detect(struct device_d *dev)
@@ -213,6 +222,33 @@ int unregister_device(struct device_d *old_dev)
}
EXPORT_SYMBOL(unregister_device);
+static int device_probe_deferred(void)
+{
+ struct device_d *dev, *tmp;
+ struct driver_d *drv;
+ int retries = 10;
+
+ do {
+ if (list_empty(&deferred))
+ break;
+
+ list_for_each_entry_safe(dev, tmp, &deferred, active) {
+ list_del(&dev->active);
+
+ if (dev->bus) {
+ bus_for_each_driver(dev->bus, drv) {
+ if (!match(drv, dev))
+ break;
+ }
+ device_probe(dev);
+ }
+ }
+ } while (retries--);
+
+ return 0;
+}
+late_initcall(device_probe_deferred);
+
struct driver_d *get_driver_by_name(const char *name)
{
struct driver_d *drv;
diff --git a/include/asm-generic/errno.h b/include/asm-generic/errno.h
index bbf493c373ae..6072f7b605bb 100644
--- a/include/asm-generic/errno.h
+++ b/include/asm-generic/errno.h
@@ -132,6 +132,7 @@
#define ERESTARTNOINTR 513
#define ERESTARTNOHAND 514 /* restart if no handler.. */
#define ENOIOCTLCMD 515 /* No ioctl command */
+#define EPROBE_DEFER 517 /* Driver requests probe retry */
#define ENOTSUPP 524 /* Operation is not supported */
--
2.1.0
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