diff mbox series

ACPI / button: fix handling lid state changes when input device closed

Message ID 20201005051125.GA3245495@dtor-ws (mailing list archive)
State Mainlined, archived
Headers show
Series ACPI / button: fix handling lid state changes when input device closed | expand

Commit Message

Dmitry Torokhov Oct. 5, 2020, 5:11 a.m. UTC 
The original intent of 84d3f6b76447 was to delay evaluating lid state until
all drivers have been loaded, with input device being opened from userspace
serving as a signal for this condition. Let's ensure that state updates
happen even if userspace closed (or in the future inhibited) input device.

Note that if we go through suspend/resume cycle we assume the system has
been fully initialized even if LID input device has not been opened yet.

This has a side-effect of fixing access to input->users outside of
input->mutex protections by the way of eliminating said accesses and using
driver private flag.

Fixes: 84d3f6b76447 ("ACPI / button: Delay acpi_lid_initialize_state() until first user space open")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/acpi/button.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

Comments

Hans de Goede Oct. 5, 2020, 8:05 a.m. UTC | #1 
Hi,

On 10/5/20 7:11 AM, dmitry.torokhov@gmail.com wrote:
> The original intent of 84d3f6b76447 was to delay evaluating lid state until
> all drivers have been loaded, with input device being opened from userspace
> serving as a signal for this condition. Let's ensure that state updates
> happen even if userspace closed (or in the future inhibited) input device.
> 
> Note that if we go through suspend/resume cycle we assume the system has
> been fully initialized even if LID input device has not been opened yet.
> 
> This has a side-effect of fixing access to input->users outside of
> input->mutex protections by the way of eliminating said accesses and using
> driver private flag.
> 
> Fixes: 84d3f6b76447 ("ACPI / button: Delay acpi_lid_initialize_state() until first user space open")
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> ---
>   drivers/acpi/button.c | 13 +++++++------
>   1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
> index 78cfc70cb320..b8dd51d8f96d 100644
> --- a/drivers/acpi/button.c
> +++ b/drivers/acpi/button.c
> @@ -154,6 +154,7 @@ struct acpi_button {
>   	int last_state;
>   	ktime_t last_time;
>   	bool suspended;
> +	bool lid_state_initialized;
>   };
>   
>   static struct acpi_device *lid_device;
> @@ -384,6 +385,8 @@ static int acpi_lid_update_state(struct acpi_device *device,
>   
>   static void acpi_lid_initialize_state(struct acpi_device *device)
>   {
> +	struct acpi_button *button = acpi_driver_data(device);
> +
>   	switch (lid_init_state) {
>   	case ACPI_BUTTON_LID_INIT_OPEN:
>   		(void)acpi_lid_notify_state(device, 1);
> @@ -395,13 +398,14 @@ static void acpi_lid_initialize_state(struct acpi_device *device)
>   	default:
>   		break;
>   	}
> +
> +	button->lid_state_initialized = true;
>   }
>   
>   static void acpi_button_notify(struct acpi_device *device, u32 event)
>   {
>   	struct acpi_button *button = acpi_driver_data(device);
>   	struct input_dev *input;
> -	int users;
>   
>   	switch (event) {
>   	case ACPI_FIXED_HARDWARE_EVENT:
> @@ -410,10 +414,7 @@ static void acpi_button_notify(struct acpi_device *device, u32 event)
>   	case ACPI_BUTTON_NOTIFY_STATUS:
>   		input = button->input;
>   		if (button->type == ACPI_BUTTON_TYPE_LID) {
> -			mutex_lock(&button->input->mutex);
> -			users = button->input->users;
> -			mutex_unlock(&button->input->mutex);
> -			if (users)
> +			if (button->lid_state_initialized)
>   				acpi_lid_update_state(device, true);
>   		} else {
>   			int keycode;
> @@ -458,7 +459,7 @@ static int acpi_button_resume(struct device *dev)
>   	struct acpi_button *button = acpi_driver_data(device);
>   
>   	button->suspended = false;
> -	if (button->type == ACPI_BUTTON_TYPE_LID && button->input->users) {
> +	if (button->type == ACPI_BUTTON_TYPE_LID) {
>   		button->last_state = !!acpi_lid_evaluate_state(device);
>   		button->last_time = ktime_get();
>   		acpi_lid_initialize_state(device);
>
Rafael J. Wysocki Oct. 5, 2020, 11:29 a.m. UTC | #2 
On Mon, Oct 5, 2020 at 7:11 AM <dmitry.torokhov@gmail.com> wrote:
>
> The original intent of 84d3f6b76447 was to delay evaluating lid state until
> all drivers have been loaded, with input device being opened from userspace
> serving as a signal for this condition. Let's ensure that state updates
> happen even if userspace closed (or in the future inhibited) input device.
>
> Note that if we go through suspend/resume cycle we assume the system has
> been fully initialized even if LID input device has not been opened yet.
>
> This has a side-effect of fixing access to input->users outside of
> input->mutex protections by the way of eliminating said accesses and using
> driver private flag.
>
> Fixes: 84d3f6b76447 ("ACPI / button: Delay acpi_lid_initialize_state() until first user space open")
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
>  drivers/acpi/button.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
> index 78cfc70cb320..b8dd51d8f96d 100644
> --- a/drivers/acpi/button.c
> +++ b/drivers/acpi/button.c
> @@ -154,6 +154,7 @@ struct acpi_button {
>         int last_state;
>         ktime_t last_time;
>         bool suspended;
> +       bool lid_state_initialized;
>  };
>
>  static struct acpi_device *lid_device;
> @@ -384,6 +385,8 @@ static int acpi_lid_update_state(struct acpi_device *device,
>
>  static void acpi_lid_initialize_state(struct acpi_device *device)
>  {
> +       struct acpi_button *button = acpi_driver_data(device);
> +
>         switch (lid_init_state) {
>         case ACPI_BUTTON_LID_INIT_OPEN:
>                 (void)acpi_lid_notify_state(device, 1);
> @@ -395,13 +398,14 @@ static void acpi_lid_initialize_state(struct acpi_device *device)
>         default:
>                 break;
>         }
> +
> +       button->lid_state_initialized = true;
>  }
>
>  static void acpi_button_notify(struct acpi_device *device, u32 event)
>  {
>         struct acpi_button *button = acpi_driver_data(device);
>         struct input_dev *input;
> -       int users;
>
>         switch (event) {
>         case ACPI_FIXED_HARDWARE_EVENT:
> @@ -410,10 +414,7 @@ static void acpi_button_notify(struct acpi_device *device, u32 event)
>         case ACPI_BUTTON_NOTIFY_STATUS:
>                 input = button->input;
>                 if (button->type == ACPI_BUTTON_TYPE_LID) {
> -                       mutex_lock(&button->input->mutex);
> -                       users = button->input->users;
> -                       mutex_unlock(&button->input->mutex);
> -                       if (users)
> +                       if (button->lid_state_initialized)
>                                 acpi_lid_update_state(device, true);
>                 } else {
>                         int keycode;
> @@ -458,7 +459,7 @@ static int acpi_button_resume(struct device *dev)
>         struct acpi_button *button = acpi_driver_data(device);
>
>         button->suspended = false;
> -       if (button->type == ACPI_BUTTON_TYPE_LID && button->input->users) {
> +       if (button->type == ACPI_BUTTON_TYPE_LID) {
>                 button->last_state = !!acpi_lid_evaluate_state(device);
>                 button->last_time = ktime_get();
>                 acpi_lid_initialize_state(device);
> --

Applied as 5.10 material with the R-by from Hans, thanks!
diff mbox series

Patch

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 78cfc70cb320..b8dd51d8f96d 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -154,6 +154,7 @@  struct acpi_button {
 	int last_state;
 	ktime_t last_time;
 	bool suspended;
+	bool lid_state_initialized;
 };
 
 static struct acpi_device *lid_device;
@@ -384,6 +385,8 @@  static int acpi_lid_update_state(struct acpi_device *device,
 
 static void acpi_lid_initialize_state(struct acpi_device *device)
 {
+	struct acpi_button *button = acpi_driver_data(device);
+
 	switch (lid_init_state) {
 	case ACPI_BUTTON_LID_INIT_OPEN:
 		(void)acpi_lid_notify_state(device, 1);
@@ -395,13 +398,14 @@  static void acpi_lid_initialize_state(struct acpi_device *device)
 	default:
 		break;
 	}
+
+	button->lid_state_initialized = true;
 }
 
 static void acpi_button_notify(struct acpi_device *device, u32 event)
 {
 	struct acpi_button *button = acpi_driver_data(device);
 	struct input_dev *input;
-	int users;
 
 	switch (event) {
 	case ACPI_FIXED_HARDWARE_EVENT:
@@ -410,10 +414,7 @@  static void acpi_button_notify(struct acpi_device *device, u32 event)
 	case ACPI_BUTTON_NOTIFY_STATUS:
 		input = button->input;
 		if (button->type == ACPI_BUTTON_TYPE_LID) {
-			mutex_lock(&button->input->mutex);
-			users = button->input->users;
-			mutex_unlock(&button->input->mutex);
-			if (users)
+			if (button->lid_state_initialized)
 				acpi_lid_update_state(device, true);
 		} else {
 			int keycode;
@@ -458,7 +459,7 @@  static int acpi_button_resume(struct device *dev)
 	struct acpi_button *button = acpi_driver_data(device);
 
 	button->suspended = false;
-	if (button->type == ACPI_BUTTON_TYPE_LID && button->input->users) {
+	if (button->type == ACPI_BUTTON_TYPE_LID) {
 		button->last_state = !!acpi_lid_evaluate_state(device);
 		button->last_time = ktime_get();
 		acpi_lid_initialize_state(device);