linux-kernel - [PATCH AUTOSEL 4.19 02/57] gpio: pxa: handle corner case of unprobed device

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Date:   Fri, 29 Mar 2019 21:27:55 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Robert Jarzmik <robert.jarzmik@...e.fr>,
        Linus Walleij <linus.walleij@...aro.org>,
        Sasha Levin <sashal@...nel.org>, linux-gpio@...r.kernel.org
Subject: [PATCH AUTOSEL 4.19 02/57] gpio: pxa: handle corner case of unprobed device

From: Robert Jarzmik <robert.jarzmik@...e.fr>

[ Upstream commit 9ce3ebe973bf4073426f35f282c6b955ed802765 ]

In the corner case where the gpio driver probe fails, for whatever
reason, the suspend and resume handlers will still be called as they
have to be registered as syscore operations. This applies as well when
no probe was called while the driver has been built in the kernel.

Nicolas tracked this in :
https://bugzilla.kernel.org/show_bug.cgi?id=200905

Therefore, add a failsafe in these function, and test if a proper probe
succeeded and the driver is functional.

Signed-off-by: Robert Jarzmik <robert.jarzmik@...e.fr>
Reported-by: Nicolas Chauvet <kwizart@...il.com>
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpio/gpio-pxa.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
index eb27fa76e8fc..bcc6be4a5cb2 100644
--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -777,6 +777,9 @@ static int pxa_gpio_suspend(void)
 	struct pxa_gpio_bank *c;
 	int gpio;
 
+	if (!pchip)
+		return 0;
+
 	for_each_gpio_bank(gpio, c, pchip) {
 		c->saved_gplr = readl_relaxed(c->regbase + GPLR_OFFSET);
 		c->saved_gpdr = readl_relaxed(c->regbase + GPDR_OFFSET);
@@ -795,6 +798,9 @@ static void pxa_gpio_resume(void)
 	struct pxa_gpio_bank *c;
 	int gpio;
 
+	if (!pchip)
+		return;
+
 	for_each_gpio_bank(gpio, c, pchip) {
 		/* restore level with set/clear */
 		writel_relaxed(c->saved_gplr, c->regbase + GPSR_OFFSET);
-- 
2.19.1