The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From cf1ad559a20d1930aa7b47a52f54e1f8718de301 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= mirq-linux@rere.qmqm.pl Date: Mon, 2 Nov 2020 22:27:27 +0100 Subject: [PATCH] regulator: defer probe when trying to get voltage from unresolved supply MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
regulator_get_voltage_rdev() is called in regulator probe() when applying machine constraints. The "fixed" commit exposed the problem that non-bypassed regulators can forward the request to its parent (like bypassed ones) supply. Return -EPROBE_DEFER when the supply is expected but not resolved yet.
Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator") Cc: stable@vger.kernel.org Signed-off-by: Michał Mirosław mirq-linux@rere.qmqm.pl Reported-by: Ondřej Jirman megous@megous.com Reported-by: Corentin Labbe clabbe.montjoie@gmail.com Tested-by: Ondřej Jirman megous@megous.com Link: https://lore.kernel.org/r/a9041d68b4d35e4a2dd71629c8a6422662acb5ee.160435193... Signed-off-by: Mark Brown broonie@kernel.org
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index a4ffd71696da..a5ad553da8cd 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4165,6 +4165,8 @@ int regulator_get_voltage_rdev(struct regulator_dev *rdev) ret = rdev->desc->fixed_uV; } else if (rdev->supply) { ret = regulator_get_voltage_rdev(rdev->supply->rdev); + } else if (rdev->supply_name) { + return -EPROBE_DEFER; } else { return -EINVAL; }