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authorJohn Stultz <john.stultz@linaro.org>2020-02-25 05:08:23 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-03-04 18:11:44 +0100
commitc8c43cee29f6ca2575c953ae600263690db28f41 (patch)
tree5be9b1416296cd29c26d38638ff2320de182697a /drivers/base/dd.c
parente94f62b7140fa3da4c69a685b2e73ef52dd32c51 (diff)
downloadlinux-c8c43cee29f6ca2575c953ae600263690db28f41.tar.bz2
driver core: Fix driver_deferred_probe_check_state() logic
driver_deferred_probe_check_state() has some uninituitive behavior. * From boot to late_initcall, it returns -EPROBE_DEFER * From late_initcall to the deferred_probe_timeout (if set) it returns -ENODEV * If the deferred_probe_timeout it set, after it fires, it returns -ETIMEDOUT This is a bit confusing, as its useful to have the function return -EPROBE_DEFER while the timeout is still running. This behavior has resulted in the somwhat duplicative driver_deferred_probe_check_state_continue() function being added. Thus this patch tries to improve the logic, so that it behaves as such: * If late_initcall has passed, and modules are not enabled it returns -ENODEV * If modules are enabled and deferred_probe_timeout is set, it returns -EPROBE_DEFER until the timeout, afterwhich it returns -ETIMEDOUT. * In all other cases, it returns -EPROBE_DEFER This will make the deferred_probe_timeout value much more functional, and will allow us to consolidate the driver_deferred_probe_check_state() and driver_deferred_probe_check_state_continue() logic in a later patch. Cc: linux-pm@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kevin Hilman <khilman@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Rob Herring <robh@kernel.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Link: https://lore.kernel.org/r/20200225050828.56458-2-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/dd.c')
-rw-r--r--drivers/base/dd.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index b25bcab2a26b..d75b34de6964 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -237,24 +237,26 @@ __setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
static int __driver_deferred_probe_check_state(struct device *dev)
{
- if (!initcalls_done)
- return -EPROBE_DEFER;
+ if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done)
+ return -ENODEV;
if (!deferred_probe_timeout) {
dev_WARN(dev, "deferred probe timeout, ignoring dependency");
return -ETIMEDOUT;
}
- return 0;
+ return -EPROBE_DEFER;
}
/**
* driver_deferred_probe_check_state() - Check deferred probe state
* @dev: device to check
*
- * Returns -ENODEV if init is done and all built-in drivers have had a chance
- * to probe (i.e. initcalls are done), -ETIMEDOUT if deferred probe debug
- * timeout has expired, or -EPROBE_DEFER if none of those conditions are met.
+ * Return:
+ * -ENODEV if initcalls have completed and modules are disabled.
+ * -ETIMEDOUT if the deferred probe timeout was set and has expired
+ * and modules are enabled.
+ * -EPROBE_DEFER in other cases.
*
* Drivers or subsystems can opt-in to calling this function instead of directly
* returning -EPROBE_DEFER.
@@ -264,7 +266,7 @@ int driver_deferred_probe_check_state(struct device *dev)
int ret;
ret = __driver_deferred_probe_check_state(dev);
- if (ret < 0)
+ if (ret != -ENODEV)
return ret;
dev_warn(dev, "ignoring dependency for device, assuming no driver");
@@ -292,7 +294,7 @@ int driver_deferred_probe_check_state_continue(struct device *dev)
int ret;
ret = __driver_deferred_probe_check_state(dev);
- if (ret < 0)
+ if (ret != -ENODEV)
return ret;
return -EPROBE_DEFER;