linux-kernel - [PATCH fixes v3] pinctrl: Really force states during suspend/resume

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Date:   Wed,  1 Mar 2017 10:32:57 -0800
From:   Florian Fainelli <f.fainelli@...il.com>
To:     linux-kernel@...r.kernel.org, linus.walleij@...aro.org
Cc:     swarren@...dia.com, andy.shevchenko@...il.com, alcooperx@...il.com,
        Florian Fainelli <f.fainelli@...il.com>,
        linux-gpio@...r.kernel.org (open list:PIN CONTROL SUBSYSTEM)
Subject: [PATCH fixes v3] pinctrl: Really force states during suspend/resume

In case a platform only defaults a "default" set of pins, but not a
"sleep" set of pins, and this particular platform suspends and resumes
in a way that the pin states are not preserved by the hardware, when we
resume, we would call pinctrl_single_resume() -> pinctrl_force_default()
-> pinctrl_select_state() and the first thing we do is check that the
pins state is the same as before, and do nothing.

In order to fix this, decouple the actual state change from
pinctrl_select_state() and move it pinctrl_commit_state(), while keeping
the p->state == state check in pinctrl_select_state() not to change the
caller assumptions. pinctrl_force_sleep() and pinctrl_force_default()
are updated to bypass the state check by calling pinctrl_commit_state().

Fixes: 6e5e959dde0d ("pinctrl: API changes to support multiple states per device")
Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
---
Changes in v3:

- move the state check to pinctrl_select_state

Changes in v2:

- rename __pinctrl_select_state to pinctrl_commit_state

 drivers/pinctrl/core.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index fb38e208f32d..735d8f7f9d71 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -992,19 +992,16 @@ struct pinctrl_state *pinctrl_lookup_state(struct pinctrl *p,
 EXPORT_SYMBOL_GPL(pinctrl_lookup_state);
 
 /**
- * pinctrl_select_state() - select/activate/program a pinctrl state to HW
+ * pinctrl_commit_state() - select/activate/program a pinctrl state to HW
  * @p: the pinctrl handle for the device that requests configuration
  * @state: the state handle to select/activate/program
  */
-int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
+static int pinctrl_commit_state(struct pinctrl *p, struct pinctrl_state *state)
 {
 	struct pinctrl_setting *setting, *setting2;
 	struct pinctrl_state *old_state = p->state;
 	int ret;
 
-	if (p->state == state)
-		return 0;
-
 	if (p->state) {
 		/*
 		 * For each pinmux setting in the old state, forget SW's record
@@ -1068,6 +1065,19 @@ int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
 
 	return ret;
 }
+
+/**
+ * pinctrl_select_state() - select/activate/program a pinctrl state to HW
+ * @p: the pinctrl handle for the device that requests configuration
+ * @state: the state handle to select/activate/program
+ */
+int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
+{
+	if (p->state == state)
+		return 0;
+
+	return pinctrl_commit_state(p, state);
+}
 EXPORT_SYMBOL_GPL(pinctrl_select_state);
 
 static void devm_pinctrl_release(struct device *dev, void *res)
@@ -1236,7 +1246,7 @@ void pinctrl_unregister_map(struct pinctrl_map const *map)
 int pinctrl_force_sleep(struct pinctrl_dev *pctldev)
 {
 	if (!IS_ERR(pctldev->p) && !IS_ERR(pctldev->hog_sleep))
-		return pinctrl_select_state(pctldev->p, pctldev->hog_sleep);
+		return pinctrl_commit_state(pctldev->p, pctldev->hog_sleep);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pinctrl_force_sleep);
@@ -1248,7 +1258,7 @@ EXPORT_SYMBOL_GPL(pinctrl_force_sleep);
 int pinctrl_force_default(struct pinctrl_dev *pctldev)
 {
 	if (!IS_ERR(pctldev->p) && !IS_ERR(pctldev->hog_default))
-		return pinctrl_select_state(pctldev->p, pctldev->hog_default);
+		return pinctrl_commit_state(pctldev->p, pctldev->hog_default);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pinctrl_force_default);
-- 
2.9.3