[PATCH 4.14 122/239] power: reset: at91-poweroff: do not procede if at91_shdwc is allocated

[Greg Kroah-Hartman]

From: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>

[ Upstream commit 9f1e44774be578fb92776add95f1fcaf8284d692 ]

There should be only one instance of struct shdwc in the system. This is
referenced through at91_shdwc. Return in probe if at91_shdwc is already
allocated.

Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/power/reset/at91-sama5d2_shdwc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index 31080c2541249..037976a1fe40b 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -246,6 +246,9 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 	if (!pdev->dev.of_node)
 		return -ENODEV;
 
+	if (at91_shdwc)
+		return -EBUSY;
+
 	at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL);
 	if (!at91_shdwc)
 		return -ENOMEM;
-- 
2.20.1