Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Received-SPF: Pass (protection.outlook.com: domain of analog.com designates
 137.71.25.57 as permitted sender) receiver=protection.outlook.com;
 client-ip=137.71.25.57; helo=nwd2mta4.analog.com;
From:   <michael.hennerich@analog.com>
To:     <linus.walleij@linaro.org>
CC:     <linux-gpio@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <baijiaju1990@gmail.com>,
        Michael Hennerich <michael.hennerich@analog.com>
Subject: [PATCH] drivers: gpio: gpio-adp5588: Fix sleep-in-atomic-context bug
Date:   Mon, 13 Aug 2018 15:57:44 +0200
Message-ID: <1534168664-13034-1-git-send-email-michael.hennerich@analog.com>
MIME-Version: 1.0
Content-Type: text/plain
SpamDiagnosticOutput: 1:99
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Aug 2018 13:53:47.1216
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 8c5e8d31-563d-4455-8cee-08d601243106
X-MS-Exchange-CrossTenant-Id: eaa689b4-8f87-40e0-9c6f-7228de4d754a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=eaa689b4-8f87-40e0-9c6f-7228de4d754a;Ip=[137.71.25.57];Helo=[nwd2mta4.analog.com]
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN3PR0301MB1217
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Michael Hennerich <michael.hennerich@analog.com>

This fixes:
[BUG] gpio: gpio-adp5588: A possible sleep-in-atomic-context bug
                          in adp5588_gpio_write()
[BUG] gpio: gpio-adp5588: A possible sleep-in-atomic-context bug
                          in adp5588_gpio_direction_input()

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
---
 drivers/gpio/gpio-adp5588.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-adp5588.c b/drivers/gpio/gpio-adp5588.c
index e717f8d..202d367 100644
--- a/drivers/gpio/gpio-adp5588.c
+++ b/drivers/gpio/gpio-adp5588.c
@@ -41,6 +41,8 @@ struct adp5588_gpio {
 	uint8_t int_en[3];
 	uint8_t irq_mask[3];
 	uint8_t irq_stat[3];
+	uint8_t int_input_en[3];
+	uint8_t int_lvl_cached[3];
 };
 
 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
@@ -173,12 +175,28 @@ static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
 	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 	int i;
 
-	for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
+	for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
+		if (dev->int_input_en[i]) {
+			mutex_lock(&dev->lock);
+			dev->dir[i] &= ~dev->int_input_en[i];
+			dev->int_input_en[i] = 0;
+			adp5588_gpio_write(dev->client, GPIO_DIR1 + i,
+					   dev->dir[i]);
+			mutex_unlock(&dev->lock);
+		}
+
+		if (dev->int_lvl_cached[i] != dev->int_lvl[i]) {
+			dev->int_lvl_cached[i] = dev->int_lvl[i];
+			adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + i,
+					   dev->int_lvl[i]);
+		}
+
 		if (dev->int_en[i] ^ dev->irq_mask[i]) {
 			dev->int_en[i] = dev->irq_mask[i];
 			adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
 					   dev->int_en[i]);
 		}
+	}
 
 	mutex_unlock(&dev->irq_lock);
 }
@@ -221,9 +239,7 @@ static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
 	else
 		return -EINVAL;
 
-	adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
-	adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
-			   dev->int_lvl[bank]);
+	dev->int_input_en[bank] |= bit;
 
 	return 0;
 }
-- 
2.7.4