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PM / Domains: Return -EPROBE_DEFER if we fail to init or turn-on domain 

When a device is probed, the function dev_pm_domain_attach() is called
to see if there is a power-domain that is associated with the device and
needs to be turned on. If dev_pm_domain_attach() does not return
-EPROBE_DEFER then the device will be probed.

For devices using genpd, dev_pm_domain_attach() will call
genpd_dev_pm_attach(). If genpd_dev_pm_attach() does not find a power
domain associated with the device then it returns an error code not
equal to -EPROBE_DEFER to allow the device to be probed. However, if
genpd_dev_pm_attach() does find a power-domain that is associated with
the device, then it does not return -EPROBE_DEFER on failure and hence
the device will still be probed. Furthermore, genpd_dev_pm_attach() does
not check the error code returned by pm_genpd_poweron() to see if the
power-domain was turned on successfully.

Fix this by checking the return code from pm_genpd_poweron() and
returning -EPROBE_DEFER from genpd_dev_pm_attach on failure, if there
is a power-domain associated with the device.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
hifive-unleashed-5.1
Jon Hunter 2015-07-31 10:20:00 +01:00 committed by Rafael J. Wysocki
parent 885fb909dc
commit 311fa6adf9
1 changed files with 9 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/base/power/domain.c
View File

@ -1947,7 +1947,10 @@ static void genpd_dev_pm_sync(struct device *dev)
* Both generic and legacy Samsung-specific DT bindings are supported to keep
* backwards compatibility with existing DTBs.
*
* Returns 0 on successfully attached PM domain or negative error code.
* Returns 0 on successfully attached PM domain or negative error code. Note
* that if a power-domain exists for the device, but it cannot be found or
* turned on, then return -EPROBE_DEFER to ensure that the device is not
* probed and to re-try again later.
*/
int genpd_dev_pm_attach(struct device *dev)
{
@ -1984,7 +1987,7 @@ int genpd_dev_pm_attach(struct device *dev)
dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
__func__, PTR_ERR(pd));
of_node_put(dev->of_node);
return PTR_ERR(pd);
return -EPROBE_DEFER;
}
dev_dbg(dev, "adding to PM domain %s\n", pd->name);
@ -2002,14 +2005,15 @@ int genpd_dev_pm_attach(struct device *dev)
dev_err(dev, "failed to add to PM domain %s: %d",
pd->name, ret);
of_node_put(dev->of_node);
return ret;
goto out;
}
dev->pm_domain->detach = genpd_dev_pm_detach;
dev->pm_domain->sync = genpd_dev_pm_sync;
pm_genpd_poweron(pd);
ret = pm_genpd_poweron(pd);
return 0;
out:
return ret ? -EPROBE_DEFER : 0;
}
EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */