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From:   Marek Szyprowski <m.szyprowski@samsung.com>
To:     linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Marek Szyprowski <m.szyprowski@samsung.com>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Subject: [PATCH] Input: cyapa - add missing input core locking to
 suspend/resume functions
Date:   Mon,  9 Oct 2023 14:10:18 +0200
Message-Id: <20231009121018.1075318-1-m.szyprowski@samsung.com>
MIME-Version: 1.0
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CMS-TYPE: 201P
References: <CGME20231009121026eucas1p19ed2a6a88fa6b899ef9b915a73ad87b5@eucas1p1.samsung.com>
Precedence: bulk

Grab input->mutex during suspend/resume functions like it is done in
other input drivers. This fixes the following warning during system
suspend/resume cycle on Samsung Exynos5250-based Snow Chromebook:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 1680 at drivers/input/input.c:2291 input_device_enabled+0x68/0x6c
Modules linked in: ...
CPU: 1 PID: 1680 Comm: kworker/u4:12 Tainted: G        W          6.6.0-rc5-next-20231009 #14109
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events_unbound async_run_entry_fn
 unwind_backtrace from show_stack+0x10/0x14
 show_stack from dump_stack_lvl+0x58/0x70
 dump_stack_lvl from __warn+0x1a8/0x1cc
 __warn from warn_slowpath_fmt+0x18c/0x1b4
 warn_slowpath_fmt from input_device_enabled+0x68/0x6c
 input_device_enabled from cyapa_gen3_set_power_mode+0x13c/0x1dc
 cyapa_gen3_set_power_mode from cyapa_reinitialize+0x10c/0x15c
 cyapa_reinitialize from cyapa_resume+0x48/0x98
 cyapa_resume from dpm_run_callback+0x90/0x298
 dpm_run_callback from device_resume+0xb4/0x258
 device_resume from async_resume+0x20/0x64
 async_resume from async_run_entry_fn+0x40/0x15c
 async_run_entry_fn from process_scheduled_works+0xbc/0x6a8
 process_scheduled_works from worker_thread+0x188/0x454
 worker_thread from kthread+0x108/0x140
 kthread from ret_from_fork+0x14/0x28
Exception stack(0xf1625fb0 to 0xf1625ff8)
...
---[ end trace 0000000000000000 ]---
...
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1680 at drivers/input/input.c:2291 input_device_enabled+0x68/0x6c
Modules linked in: ...
CPU: 1 PID: 1680 Comm: kworker/u4:12 Tainted: G        W          6.6.0-rc5-next-20231009 #14109
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events_unbound async_run_entry_fn
 unwind_backtrace from show_stack+0x10/0x14
 show_stack from dump_stack_lvl+0x58/0x70
 dump_stack_lvl from __warn+0x1a8/0x1cc
 __warn from warn_slowpath_fmt+0x18c/0x1b4
 warn_slowpath_fmt from input_device_enabled+0x68/0x6c
 input_device_enabled from cyapa_gen3_set_power_mode+0x13c/0x1dc
 cyapa_gen3_set_power_mode from cyapa_reinitialize+0x10c/0x15c
 cyapa_reinitialize from cyapa_resume+0x48/0x98
 cyapa_resume from dpm_run_callback+0x90/0x298
 dpm_run_callback from device_resume+0xb4/0x258
 device_resume from async_resume+0x20/0x64
 async_resume from async_run_entry_fn+0x40/0x15c
 async_run_entry_fn from process_scheduled_works+0xbc/0x6a8
 process_scheduled_works from worker_thread+0x188/0x454
 worker_thread from kthread+0x108/0x140
 kthread from ret_from_fork+0x14/0x28
Exception stack(0xf1625fb0 to 0xf1625ff8)
...
---[ end trace 0000000000000000 ]---

Fixes: d69f0a43c677 ("Input: use input_device_enabled()")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/input/mouse/cyapa.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
index a84098448f5b..cf23f95b5f11 100644
--- a/drivers/input/mouse/cyapa.c
+++ b/drivers/input/mouse/cyapa.c
@@ -1347,10 +1347,16 @@ static int cyapa_suspend(struct device *dev)
 	u8 power_mode;
 	int error;
 
-	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	error = mutex_lock_interruptible(&cyapa->input->mutex);
 	if (error)
 		return error;
 
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error) {
+		mutex_unlock(&cyapa->input->mutex);
+		return error;
+	}
+
 	/*
 	 * Runtime PM is enable only when device is in operational mode and
 	 * users in use, so need check it before disable it to
@@ -1385,6 +1391,8 @@ static int cyapa_suspend(struct device *dev)
 		cyapa->irq_wake = (enable_irq_wake(client->irq) == 0);
 
 	mutex_unlock(&cyapa->state_sync_lock);
+	mutex_unlock(&cyapa->input->mutex);
+
 	return 0;
 }
 
@@ -1394,6 +1402,7 @@ static int cyapa_resume(struct device *dev)
 	struct cyapa *cyapa = i2c_get_clientdata(client);
 	int error;
 
+	mutex_lock(&cyapa->input->mutex);
 	mutex_lock(&cyapa->state_sync_lock);
 
 	if (device_may_wakeup(dev) && cyapa->irq_wake) {
@@ -1412,6 +1421,7 @@ static int cyapa_resume(struct device *dev)
 	enable_irq(client->irq);
 
 	mutex_unlock(&cyapa->state_sync_lock);
+	mutex_unlock(&cyapa->input->mutex);
 	return 0;
 }
 
-- 
2.34.1