diff options
| -rw-r--r-- | drivers/base/driver.c | 56 | ||||
| -rw-r--r-- | include/asm-generic/errno.h | 1 |
2 files changed, 54 insertions, 3 deletions
diff --git a/drivers/base/driver.c b/drivers/base/driver.c index 590c97c964..6112b4953b 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 +222,47 @@ int unregister_device(struct device_d *old_dev) } EXPORT_SYMBOL(unregister_device); +/* + * Loop over list of deferred devices as long as at least one + * device is successfully probed. Devices that again request + * deferral are re-added to deferred list in device_probe(). + * For devices finally left in deferred list -EPROBE_DEFER + * becomes a fatal error. + */ +static int device_probe_deferred(void) +{ + struct device_d *dev, *tmp; + struct driver_d *drv; + bool success; + + do { + success = false; + + if (list_empty(&deferred)) + break; + + list_for_each_entry_safe(dev, tmp, &deferred, active) { + list_del(&dev->active); + dev_dbg(dev, "re-probe device\n"); + bus_for_each_driver(dev->bus, drv) { + if (match(drv, dev)) + continue; + success = true; + break; + } + } + } while (success); + + if (list_empty(&deferred)) + return 0; + + list_for_each_entry(dev, &deferred, active) + dev_err(dev, "probe permanently deferred\n"); + + 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 bbf493c373..6072f7b605 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 */ |