Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Thu, 20 Feb 2020 11:28:30 +0100 | Subject | Re: [PATCH v4 1/6] driver core: Fix driver_deferred_probe_check_state() logic |
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On Thu, Feb 20, 2020 at 6:05 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 deferred_probe_timeout is set, it returns -EPROBE_DEFER > until the timeout, afterwhich it returns -ETIMEDOUT. > > * If deferred_probe_timeout is not set (-1), it returns > -EPROBE_DEFER until late_initcall, after which it returns > > 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: 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> > Change-Id: I8349b7a403ce8cbce485ea0a0a5512fddffb635c > --- > v4: > * Simplified logic suggested by Andy Shevchenko > * Clarified commit message to focus on logic change > --- > drivers/base/dd.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index b25bcab2a26b..bb383dca39c1 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -237,7 +237,7 @@ __setup("deferred_probe_timeout=", deferred_probe_timeout_setup); > > static int __driver_deferred_probe_check_state(struct device *dev) > { > - if (!initcalls_done) > + if (!initcalls_done || deferred_probe_timeout > 0) > return -EPROBE_DEFER;
Makes sense to me.
> > if (!deferred_probe_timeout) { > @@ -252,9 +252,11 @@ static int __driver_deferred_probe_check_state(struct device *dev) > * 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. > + * Returnes -EPROBE_DEFER if initcalls have not completed, or the deferred
s/Returnes/Returns/
And I would write
* Return: * -EPROBE_DEFER if initcalls have not completed, or the deferred * probe timeout is set, but not expried. * -ETIMEDOUT if the deferred probe timeout was set and has expired. * -ENODEV if initcalls have completed and the deferred probe timeout was not set.
> + * probe timeout is set, but not expried. > + * Returns -ETIMEDOUT if the probe timeout was set and has expired. > + * Returns -ENODEV if initcalls have completed and the deferred probe timeout > + * was not set. > * > * Drivers or subsystems can opt-in to calling this function instead of directly > * returning -EPROBE_DEFER. > --
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