Commit b2c985e7 authored by Henrique de Moraes Holschuh's avatar Henrique de Moraes Holschuh Committed by Len Brown
Browse files

ACPI: thinkpad-acpi: refactor hotkey_get and hotkey_set (v2) 



Refactor and organize the code a bit for the NVRAM polling support:

1. Split hotkey_get/set into hotkey_status_get/set and hotkey_mask_get/set;
2. Cache the status of hot key mask for later driver use;
3. Make sure the cache of hot key mask is refreshed when needed;
4. log a printk notice when the firmware doesn't set the hot key
   mask to exactly what we asked it to;
5. Add proper locking to the data structures.

Only (4) should be user-noticeable, but there is a chance (5) fixes
some unknown/unreported race conditions.

Signed-off-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 0f089147

drivers/misc/thinkpad_acpi.c

+109 −75
Original line number Diff line number Diff line
@@ -777,6 +777,7 @@ static int hotkey_orig_status; 
static u32 hotkey_orig_mask;

static u32 hotkey_all_mask;

static u32 hotkey_reserved_mask;

static u32 hotkey_mask;



static u16 *hotkey_keycode_map;
@@ -789,15 +790,76 @@ static int hotkey_get_wlsw(int *status) 
	return 0;

}



/*

 * Call with hotkey_mutex held

 */

static int hotkey_mask_get(void)

{

	if (tp_features.hotkey_mask) {

		if (!acpi_evalf(hkey_handle, &hotkey_mask, "DHKN", "d"))

			return -EIO;

	}



	return 0;

}



/*

 * Call with hotkey_mutex held

 */

static int hotkey_mask_set(u32 mask)

{

	int i;

	int rc = 0;



	if (tp_features.hotkey_mask) {

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

			u32 m = 1 << i;

			if (!acpi_evalf(hkey_handle,

					NULL, "MHKM", "vdd", i + 1,

					!!(mask & m))) {

				rc = -EIO;

				break;

			} else {

				hotkey_mask = (hotkey_mask & ~m) | (mask & m);

			}

		}



		/* hotkey_mask_get must be called unconditionally below */

		if (!hotkey_mask_get() && !rc && hotkey_mask != mask) {

			printk(IBM_NOTICE

			       "requested hot key mask 0x%08x, but "

			       "firmware forced it to 0x%08x\n",

			       mask, hotkey_mask);

		}

	}



	return rc;

}



static int hotkey_status_get(int *status)

{

	if (!acpi_evalf(hkey_handle, status, "DHKC", "d"))

		return -EIO;



	return 0;

}



static int hotkey_status_set(int status)

{

	if (!acpi_evalf(hkey_handle, NULL, "MHKC", "vd", status))

		return -EIO;



	return 0;

}



/* sysfs hotkey enable ------------------------------------------------- */

static ssize_t hotkey_enable_show(struct device *dev,

			   struct device_attribute *attr,

			   char *buf)

{

	int res, status;

	u32 mask;



	res = hotkey_get(&status, &mask);

	res = hotkey_status_get(&status);

	if (res)

		return res;
@@ -809,15 +871,12 @@ static ssize_t hotkey_enable_store(struct device *dev, 
			    const char *buf, size_t count)

{

	unsigned long t;

	int res, status;

	u32 mask;

	int res;



	if (parse_strtoul(buf, 1, &t))

		return -EINVAL;



	res = hotkey_get(&status, &mask);

	if (!res)

		res = hotkey_set(t, mask);

	res = hotkey_status_set(t);



	return (res) ? res : count;

}
@@ -831,14 +890,15 @@ static ssize_t hotkey_mask_show(struct device *dev, 
			   struct device_attribute *attr,

			   char *buf)

{

	int res, status;

	u32 mask;

	int res;



	res = hotkey_get(&status, &mask);

	if (res)

		return res;

	if (mutex_lock_interruptible(&hotkey_mutex))

		return -ERESTARTSYS;

	res = hotkey_mask_get();

	mutex_unlock(&hotkey_mutex);



	return snprintf(buf, PAGE_SIZE, "0x%08x\n", mask);

	return (res)?

		res : snprintf(buf, PAGE_SIZE, "0x%08x\n", hotkey_mask);

}



static ssize_t hotkey_mask_store(struct device *dev,
@@ -846,15 +906,16 @@ static ssize_t hotkey_mask_store(struct device *dev, 
			    const char *buf, size_t count)

{

	unsigned long t;

	int res, status;

	u32 mask;

	int res;



	if (parse_strtoul(buf, 0xffffffffUL, &t))

		return -EINVAL;



	res = hotkey_get(&status, &mask);

	if (!res)

		hotkey_set(status, t);

	if (mutex_lock_interruptible(&hotkey_mutex))

		return -ERESTARTSYS;



	res = hotkey_mask_set(t);

	mutex_unlock(&hotkey_mutex);



	return (res) ? res : count;

}
@@ -1123,12 +1184,17 @@ static int __init hotkey_init(struct ibm_init_struct *iibm) 
			}

		}



		res = hotkey_get(&hotkey_orig_status, &hotkey_orig_mask);

		res = hotkey_status_get(&hotkey_orig_status);

		if (!res && tp_features.hotkey_mask) {

			res = add_many_to_attr_set(hotkey_dev_attributes,

			res = hotkey_mask_get();

			hotkey_orig_mask = hotkey_mask;

			if (!res) {

				res = add_many_to_attr_set(

					hotkey_dev_attributes,

					hotkey_mask_attributes,

					ARRAY_SIZE(hotkey_mask_attributes));

			}

		}



		/* Not all thinkpads have a hardware radio switch */

		if (!res && acpi_evalf(hkey_handle, &status, "WLSW", "qd")) {
@@ -1191,7 +1257,10 @@ static int __init hotkey_init(struct ibm_init_struct *iibm) 


		dbg_printk(TPACPI_DBG_INIT,

				"enabling hot key handling\n");

		res = hotkey_set(1, (hotkey_all_mask & ~hotkey_reserved_mask)

		res = hotkey_status_set(1);

		if (res)

			return res;

		res = hotkey_mask_set((hotkey_all_mask & ~hotkey_reserved_mask)

					| hotkey_orig_mask);

		if (res)

			return res;
@@ -1207,13 +1276,12 @@ static int __init hotkey_init(struct ibm_init_struct *iibm) 


static void hotkey_exit(void)

{

	int res;



	if (tp_features.hotkey) {

		dbg_printk(TPACPI_DBG_EXIT, "restoring original hot key mask\n");

		res = hotkey_set(hotkey_orig_status, hotkey_orig_mask);

		if (res)

			printk(IBM_ERR "failed to restore hotkey to BIOS defaults\n");

		/* no short-circuit boolean operator below! */

		if ((hotkey_mask_set(hotkey_orig_mask) |

		     hotkey_status_set(hotkey_orig_status)) != 0)

			printk(IBM_ERR "failed to restore hot key mask to BIOS defaults\n");

	}



	if (hotkey_dev_attributes) {
@@ -1349,50 +1417,15 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event) 


static void hotkey_resume(void)

{

	if (hotkey_mask_get())

		printk(IBM_ERR "error while trying to read hot key mask from firmware\n");

	tpacpi_input_send_radiosw();

}



/*

 * Call with hotkey_mutex held

 */

static int hotkey_get(int *status, u32 *mask)

{

	if (!acpi_evalf(hkey_handle, status, "DHKC", "d"))

		return -EIO;



	if (tp_features.hotkey_mask)

		if (!acpi_evalf(hkey_handle, mask, "DHKN", "d"))

			return -EIO;



	return 0;

}



/*

 * Call with hotkey_mutex held

 */

static int hotkey_set(int status, u32 mask)

{

	int i;



	if (!acpi_evalf(hkey_handle, NULL, "MHKC", "vd", status))

		return -EIO;



	if (tp_features.hotkey_mask)

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

			int bit = ((1 << i) & mask) != 0;

			if (!acpi_evalf(hkey_handle,

					NULL, "MHKM", "vdd", i + 1, bit))

				return -EIO;

		}



	return 0;

}



/* procfs -------------------------------------------------------------- */

static int hotkey_read(char *p)

{

	int res, status;

	u32 mask;

	int len = 0;



	if (!tp_features.hotkey) {
@@ -1402,14 +1435,16 @@ static int hotkey_read(char *p) 


	if (mutex_lock_interruptible(&hotkey_mutex))

		return -ERESTARTSYS;

	res = hotkey_get(&status, &mask);

	res = hotkey_status_get(&status);

	if (!res)

		res = hotkey_mask_get();

	mutex_unlock(&hotkey_mutex);

	if (res)

		return res;



	len += sprintf(p + len, "status:\t\t%s\n", enabled(status, 0));

	if (tp_features.hotkey_mask) {

		len += sprintf(p + len, "mask:\t\t0x%08x\n", mask);

		len += sprintf(p + len, "mask:\t\t0x%08x\n", hotkey_mask);

		len += sprintf(p + len,

			       "commands:\tenable, disable, reset, <mask>\n");

	} else {
@@ -1425,7 +1460,6 @@ static int hotkey_write(char *buf) 
	int res, status;

	u32 mask;

	char *cmd;

	int do_cmd = 0;



	if (!tp_features.hotkey)

		return -ENODEV;
@@ -1433,9 +1467,8 @@ static int hotkey_write(char *buf) 
	if (mutex_lock_interruptible(&hotkey_mutex))

		return -ERESTARTSYS;



	res = hotkey_get(&status, &mask);

	if (res)

		goto errexit;

	status = -1;

	mask = hotkey_mask;



	res = 0;

	while ((cmd = next_cmd(&buf))) {
@@ -1454,11 +1487,12 @@ static int hotkey_write(char *buf) 
			res = -EINVAL;

			goto errexit;

		}

		do_cmd = 1;

	}

	if (status != -1)

		res = hotkey_status_set(status);



	if (do_cmd)

		res = hotkey_set(status, mask);

	if (!res && mask != hotkey_mask)

		res = hotkey_mask_set(mask);



errexit:

	mutex_unlock(&hotkey_mutex);

drivers/misc/thinkpad_acpi.h

+0 −2
Original line number Diff line number Diff line
@@ -461,8 +461,6 @@ static struct mutex hotkey_mutex; 


static int hotkey_init(struct ibm_init_struct *iibm);

static void hotkey_exit(void);

static int hotkey_get(int *status, u32 *mask);

static int hotkey_set(int status, u32 mask);

static void hotkey_notify(struct ibm_struct *ibm, u32 event);

static int hotkey_read(char *p);

static int hotkey_write(char *buf);

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