Commit 38831eaf authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Hans de Goede
Browse files

platform/x86: thinkpad_acpi: use lockdep annotations 



Instead of relying on free-form comments to document locking
requirements use well-known lockdep annotations.
These can also be validated at runtime make sure the invariants are not
violated.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20230704-thinkpad_acpi-lockdep-v1-2-60129548a738@weissschuh.net


Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent ce55dbe5

drivers/platform/x86/thinkpad_acpi.c

+24 −17
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ 
#include <linux/kthread.h>

#include <linux/leds.h>

#include <linux/list.h>

#include <linux/lockdep.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/nvram.h>
@@ -2071,11 +2072,11 @@ static int hotkey_get_tablet_mode(int *status) 
 * hotkey_acpi_mask accordingly.  Also resets any bits

 * from hotkey_user_mask that are unavailable to be

 * delivered (shadow requirement of the userspace ABI).

 *

 * Call with hotkey_mutex held

 */

static int hotkey_mask_get(void)

{

	lockdep_assert_held(&hotkey_mutex);



	if (tp_features.hotkey_mask) {

		u32 m = 0;
@@ -2111,8 +2112,6 @@ static void hotkey_mask_warn_incomplete_mask(void) 
 * Also calls hotkey_mask_get to update hotkey_acpi_mask.

 *

 * NOTE: does not set bits in hotkey_user_mask, but may reset them.

 *

 * Call with hotkey_mutex held

 */

static int hotkey_mask_set(u32 mask)

{
@@ -2121,6 +2120,8 @@ static int hotkey_mask_set(u32 mask) 


	const u32 fwmask = mask & ~hotkey_source_mask;



	lockdep_assert_held(&hotkey_mutex);



	if (tp_features.hotkey_mask) {

		for (i = 0; i < 32; i++) {

			if (!acpi_evalf(hkey_handle,
@@ -2152,13 +2153,13 @@ static int hotkey_mask_set(u32 mask) 


/*

 * Sets hotkey_user_mask and tries to set the firmware mask

 *

 * Call with hotkey_mutex held

 */

static int hotkey_user_mask_set(const u32 mask)

{

	int rc;



	lockdep_assert_held(&hotkey_mutex);



	/* Give people a chance to notice they are doing something that

	 * is bound to go boom on their users sooner or later */

	if (!tp_warned.hotkey_mask_ff &&
@@ -2519,21 +2520,23 @@ static int hotkey_kthread(void *data) 
	return 0;

}



/* call with hotkey_mutex held */

static void hotkey_poll_stop_sync(void)

{

	lockdep_assert_held(&hotkey_mutex);



	if (tpacpi_hotkey_task) {

		kthread_stop(tpacpi_hotkey_task);

		tpacpi_hotkey_task = NULL;

	}

}



/* call with hotkey_mutex held */

static void hotkey_poll_setup(const bool may_warn)

{

	const u32 poll_driver_mask = hotkey_driver_mask & hotkey_source_mask;

	const u32 poll_user_mask = hotkey_user_mask & hotkey_source_mask;



	lockdep_assert_held(&hotkey_mutex);



	if (hotkey_poll_freq > 0 &&

	    (poll_driver_mask ||

	     (poll_user_mask && tpacpi_inputdev->users > 0))) {
@@ -2562,9 +2565,10 @@ static void hotkey_poll_setup_safe(const bool may_warn) 
	mutex_unlock(&hotkey_mutex);

}



/* call with hotkey_mutex held */

static void hotkey_poll_set_freq(unsigned int freq)

{

	lockdep_assert_held(&hotkey_mutex);



	if (!freq)

		hotkey_poll_stop_sync();
@@ -6664,12 +6668,13 @@ static unsigned int brightness_enable = 2; /* 2 = auto, 0 = no, 1 = yes */ 


static struct mutex brightness_mutex;



/* NVRAM brightness access,

 * call with brightness_mutex held! */

/* NVRAM brightness access */

static unsigned int tpacpi_brightness_nvram_get(void)

{

	u8 lnvram;



	lockdep_assert_held(&brightness_mutex);



	lnvram = (nvram_read_byte(TP_NVRAM_ADDR_BRIGHTNESS)

		  & TP_NVRAM_MASK_LEVEL_BRIGHTNESS)

		  >> TP_NVRAM_POS_LEVEL_BRIGHTNESS;
@@ -6717,11 +6722,12 @@ static void tpacpi_brightness_checkpoint_nvram(void) 
}





/* call with brightness_mutex held! */

static int tpacpi_brightness_get_raw(int *status)

{

	u8 lec = 0;



	lockdep_assert_held(&brightness_mutex);



	switch (brightness_mode) {

	case TPACPI_BRGHT_MODE_UCMS_STEP:

		*status = tpacpi_brightness_nvram_get();
@@ -6737,12 +6743,13 @@ static int tpacpi_brightness_get_raw(int *status) 
	}

}



/* call with brightness_mutex held! */

/* do NOT call with illegal backlight level value */

static int tpacpi_brightness_set_ec(unsigned int value)

{

	u8 lec = 0;



	lockdep_assert_held(&brightness_mutex);



	if (unlikely(!acpi_ec_read(TP_EC_BACKLIGHT, &lec)))

		return -EIO;
@@ -6754,12 +6761,13 @@ static int tpacpi_brightness_set_ec(unsigned int value) 
	return 0;

}



/* call with brightness_mutex held! */

static int tpacpi_brightness_set_ucmsstep(unsigned int value)

{

	int cmos_cmd, inc;

	unsigned int current_value, i;



	lockdep_assert_held(&brightness_mutex);



	current_value = tpacpi_brightness_nvram_get();



	if (value == current_value)
@@ -8208,11 +8216,10 @@ static bool fan_select_fan2(void) 
	return true;

}



/*

 * Call with fan_mutex held

 */

static void fan_update_desired_level(u8 status)

{

	lockdep_assert_held(&fan_mutex);



	if ((status &

	     (TP_EC_FAN_AUTO | TP_EC_FAN_FULLSPEED)) == 0) {

		if (status > 7)