On Fri, Apr 10, 2015 at 03:02:43AM +0200, Sebastian Hesselbarth wrote:
> 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--);
Instead of a hardcoded loop counter I think this should be "while at least
one device successfully probed". Also if probe fails and the return
value is still -EPROBE_DEFER you have to add the device to the deferred
list again.
Sascha
--
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