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ACPI: thinkpad-acpi: refactor hotkey_get and hotkey_set (v2)
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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: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
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Henrique de Moraes Holschuh authored and Len Brown committed Feb 2, 2008
1 parent 0f08914 commit b2c985e
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Showing 2 changed files with 109 additions and 77 deletions.
184 changes: 109 additions & 75 deletions drivers/misc/thinkpad_acpi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;

Expand All @@ -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;

Expand All @@ -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;
}
Expand All @@ -831,30 +890,32 @@ 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,
struct device_attribute *attr,
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;
}
Expand Down Expand Up @@ -1123,11 +1184,16 @@ 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,
hotkey_mask_attributes,
ARRAY_SIZE(hotkey_mask_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 */
Expand Down Expand Up @@ -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;
Expand All @@ -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 hotkey mask\n");
res = hotkey_set(hotkey_orig_status, hotkey_orig_mask);
if (res)
printk(IBM_ERR "failed to restore hotkey to BIOS defaults\n");
dbg_printk(TPACPI_DBG_EXIT, "restoring original hot key mask\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) {
Expand Down Expand Up @@ -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) {
Expand All @@ -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 {
Expand All @@ -1425,17 +1460,15 @@ static int hotkey_write(char *buf)
int res, status;
u32 mask;
char *cmd;
int do_cmd = 0;

if (!tp_features.hotkey)
return -ENODEV;

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))) {
Expand All @@ -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);
Expand Down
2 changes: 0 additions & 2 deletions drivers/misc/thinkpad_acpi.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down

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