From c8c43cee29f6ca2575c953ae600263690db28f41 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 25 Feb 2020 05:08:23 +0000 Subject: [PATCH] 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 Cc: Linus Walleij Cc: Thierry Reding Cc: Mark Brown Cc: Liam Girdwood Cc: Bjorn Andersson Cc: Saravana Kannan Cc: Todd Kjos Cc: Len Brown Cc: Pavel Machek Cc: Ulf Hansson Cc: Kevin Hilman Cc: "Rafael J. Wysocki" Cc: Rob Herring Signed-off-by: John Stultz Link: https://lore.kernel.org/r/20200225050828.56458-2-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index b25bcab2a26bd..d75b34de69644 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; -- 2.30.2