| Message ID | 20200225050828.56458-2-john.stultz@linaro.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | driver core: Improve and cleanup driver_deferred_probe_check_state() | expand |
On Tue, Feb 25, 2020 at 6:08 AM John Stultz <john.stultz@linaro.org> wrote: > > 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: Rob Herring <robh@kernel.org> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > Cc: Kevin Hilman <khilman@kernel.org> > Cc: Ulf Hansson <ulf.hansson@linaro.org> > Cc: Pavel Machek <pavel@ucw.cz> > Cc: Len Brown <len.brown@intel.com> > Cc: Todd Kjos <tkjos@google.com> > Cc: Saravana Kannan <saravanak@google.com> > Cc: Bjorn Andersson <bjorn.andersson@linaro.org> > Cc: Liam Girdwood <lgirdwood@gmail.com> > Cc: Mark Brown <broonie@kernel.org> > Cc: Thierry Reding <treding@nvidia.com> > Cc: Linus Walleij <linus.walleij@linaro.org> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: linux-pm@vger.kernel.org > Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > v4: > * Simplified logic suggested by Andy Shevchenko > * Clarified commit message to focus on logic change > v5: > * Cleanup comment wording as suggested by Rafael > * Tweaked the logic to use Saravana's suggested conditionals > --- > 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 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; > -- > 2.17.1 >
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;
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: Rob Herring <robh@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Kevin Hilman <khilman@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Len Brown <len.brown@intel.com> Cc: Todd Kjos <tkjos@google.com> Cc: Saravana Kannan <saravanak@google.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Thierry Reding <treding@nvidia.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-pm@vger.kernel.org Signed-off-by: John Stultz <john.stultz@linaro.org> --- v4: * Simplified logic suggested by Andy Shevchenko * Clarified commit message to focus on logic change v5: * Cleanup comment wording as suggested by Rafael * Tweaked the logic to use Saravana's suggested conditionals --- drivers/base/dd.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)