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From:   gregkh@linuxfoundation.org
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 13/20] platform/x86: acer-wmi: Cleanup accelerometer device handling
Date:   Wed, 10 Mar 2021 14:24:50 +0100
Message-Id: <20210310132320.952294233@linuxfoundation.org>
In-Reply-To: <20210310132320.512307035@linuxfoundation.org>
References: <20210310132320.512307035@linuxfoundation.org>
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Hans de Goede <hdegoede@redhat.com>

[ Upstream commit 9feb0763e4985ccfae632de3bb2f029cc8389842 ]

Cleanup accelerometer device handling:
-Drop acer_wmi_accel_destroy instead directly call input_unregister_device.
-The information tracked by the CAP_ACCEL flag mirrors acer_wmi_accel_dev
 being NULL. Drop the CAP flag, this is a preparation change for allowing
 users to override the capability flags. Dropping the flag stops users
 from causing a NULL pointer dereference by forcing the capability.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201019185628.264473-3-hdegoede@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/platform/x86/acer-wmi.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 41311c1526a0..445e9c17f4a8 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -223,7 +223,6 @@ struct hotkey_function_type_aa {
 #define ACER_CAP_BLUETOOTH		BIT(2)
 #define ACER_CAP_BRIGHTNESS		BIT(3)
 #define ACER_CAP_THREEG			BIT(4)
-#define ACER_CAP_ACCEL			BIT(5)
 
 /*
  * Interface type flags
@@ -1528,7 +1527,7 @@ static int acer_gsensor_event(void)
 	struct acpi_buffer output;
 	union acpi_object out_obj[5];
 
-	if (!has_cap(ACER_CAP_ACCEL))
+	if (!acer_wmi_accel_dev)
 		return -1;
 
 	output.length = sizeof(out_obj);
@@ -1937,8 +1936,6 @@ static int __init acer_wmi_accel_setup(void)
 	if (err)
 		return err;
 
-	interface->capability |= ACER_CAP_ACCEL;
-
 	acer_wmi_accel_dev = input_allocate_device();
 	if (!acer_wmi_accel_dev)
 		return -ENOMEM;
@@ -1964,11 +1961,6 @@ err_free_dev:
 	return err;
 }
 
-static void acer_wmi_accel_destroy(void)
-{
-	input_unregister_device(acer_wmi_accel_dev);
-}
-
 static int __init acer_wmi_input_setup(void)
 {
 	acpi_status status;
@@ -2123,7 +2115,7 @@ static int acer_resume(struct device *dev)
 	if (has_cap(ACER_CAP_BRIGHTNESS))
 		set_u32(data->brightness, ACER_CAP_BRIGHTNESS);
 
-	if (has_cap(ACER_CAP_ACCEL))
+	if (acer_wmi_accel_dev)
 		acer_gsensor_init();
 
 	return 0;
@@ -2331,8 +2323,8 @@ error_device_alloc:
 error_platform_register:
 	if (wmi_has_guid(ACERWMID_EVENT_GUID))
 		acer_wmi_input_destroy();
-	if (has_cap(ACER_CAP_ACCEL))
-		acer_wmi_accel_destroy();
+	if (acer_wmi_accel_dev)
+		input_unregister_device(acer_wmi_accel_dev);
 
 	return err;
 }
@@ -2342,8 +2334,8 @@ static void __exit acer_wmi_exit(void)
 	if (wmi_has_guid(ACERWMID_EVENT_GUID))
 		acer_wmi_input_destroy();
 
-	if (has_cap(ACER_CAP_ACCEL))
-		acer_wmi_accel_destroy();
+	if (acer_wmi_accel_dev)
+		input_unregister_device(acer_wmi_accel_dev);
 
 	remove_debugfs();
 	platform_device_unregister(acer_platform_device);
-- 
2.30.1