linux-kernel - [PATCH v5 6/6] regulator: Use driver_deferred_probe_timeout for regulator_init_complete

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Message-Id: <20200225050828.56458-7-john.stultz@linaro.org>
Date:   Tue, 25 Feb 2020 05:08:28 +0000
From:   John Stultz <john.stultz@...aro.org>
To:     lkml <linux-kernel@...r.kernel.org>
Cc:     John Stultz <john.stultz@...aro.org>,
        Rob Herring <robh@...nel.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Pavel Machek <pavel@....cz>, Len Brown <len.brown@...el.com>,
        Todd Kjos <tkjos@...gle.com>,
        Saravana Kannan <saravanak@...gle.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Thierry Reding <treding@...dia.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-pm@...r.kernel.org
Subject: [PATCH v5 6/6] regulator: Use driver_deferred_probe_timeout for regulator_init_complete_work

The regulator_init_complete_work logic defers the cleanup for an
arbitrary 30 seconds of time to allow modules loaded by userland
to start.

This arbitrary timeout is similar to the
driver_deferred_probe_timeout value, and its been suggested we
align these so users have a method to extend the timeouts as
needed.

So this patch changes the logic to use the
driver_deferred_probe_timeout value for the delay value if it
is set (using a delay of 0 if it is not).

Cc: Rob Herring <robh@...nel.org>
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: Kevin Hilman <khilman@...nel.org>
Cc: Ulf Hansson <ulf.hansson@...aro.org>
Cc: Pavel Machek <pavel@....cz>
Cc: Len Brown <len.brown@...el.com>
Cc: Todd Kjos <tkjos@...gle.com>
Cc: Saravana Kannan <saravanak@...gle.com>
Cc: Bjorn Andersson <bjorn.andersson@...aro.org>
Cc: Liam Girdwood <lgirdwood@...il.com>
Cc: Mark Brown <broonie@...nel.org>
Cc: Thierry Reding <treding@...dia.com>
Cc: Linus Walleij <linus.walleij@...aro.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: linux-pm@...r.kernel.org
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
v4:
* Split out into its own patch, as suggested by Mark
v5:
* Try to simplify the logic a touch as suggested by Bjorn
---
 drivers/regulator/core.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index d015d99cb59d..51b6a2dea717 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5757,6 +5757,10 @@ static DECLARE_DELAYED_WORK(regulator_init_complete_work,
 
 static int __init regulator_init_complete(void)
 {
+	int delay = driver_deferred_probe_timeout;
+
+	if (delay < 0)
+		delay = 0;
 	/*
 	 * Since DT doesn't provide an idiomatic mechanism for
 	 * enabling full constraints and since it's much more natural
@@ -5767,18 +5771,17 @@ static int __init regulator_init_complete(void)
 		has_full_constraints = true;
 
 	/*
-	 * We punt completion for an arbitrary amount of time since
-	 * systems like distros will load many drivers from userspace
-	 * so consumers might not always be ready yet, this is
-	 * particularly an issue with laptops where this might bounce
-	 * the display off then on.  Ideally we'd get a notification
-	 * from userspace when this happens but we don't so just wait
-	 * a bit and hope we waited long enough.  It'd be better if
-	 * we'd only do this on systems that need it, and a kernel
-	 * command line option might be useful.
+	 * If driver_deferred_probe_timeout is set, we punt
+	 * completion for that many seconds since systems like
+	 * distros will load many drivers from userspace so consumers
+	 * might not always be ready yet, this is particularly an
+	 * issue with laptops where this might bounce the display off
+	 * then on.  Ideally we'd get a notification from userspace
+	 * when this happens but we don't so just wait a bit and hope
+	 * we waited long enough.  It'd be better if we'd only do
+	 * this on systems that need it.
 	 */
-	schedule_delayed_work(&regulator_init_complete_work,
-			      msecs_to_jiffies(30000));
+	schedule_delayed_work(&regulator_init_complete_work, delay * HZ);
 
 	return 0;
 }
-- 
2.17.1