Using guard notation makes the code more compact and error handling
more robust by ensuring that locks are released in all code paths
when control leaves critical section.
Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
---
drivers/input/serio/i8042.c | 204 +++++++++++++++---------------------
1 file changed, 82 insertions(+), 122 deletions(-)
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 674cd155ec8f..86916fe3925f 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -197,42 +197,26 @@ EXPORT_SYMBOL(i8042_unlock_chip);
int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
struct serio *serio))
{
- unsigned long flags;
- int ret = 0;
+ guard(spinlock_irqsave)(&i8042_lock);
- spin_lock_irqsave(&i8042_lock, flags);
-
- if (i8042_platform_filter) {
- ret = -EBUSY;
- goto out;
- }
+ if (i8042_platform_filter)
+ return -EBUSY;
i8042_platform_filter = filter;
-
-out:
- spin_unlock_irqrestore(&i8042_lock, flags);
- return ret;
+ return 0;
}
EXPORT_SYMBOL(i8042_install_filter);
int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
struct serio *port))
{
- unsigned long flags;
- int ret = 0;
-
- spin_lock_irqsave(&i8042_lock, flags);
+ guard(spinlock_irqsave)(&i8042_lock);
- if (i8042_platform_filter != filter) {
- ret = -EINVAL;
- goto out;
- }
+ if (i8042_platform_filter != filter)
+ return -EINVAL;
i8042_platform_filter = NULL;
-
-out:
- spin_unlock_irqrestore(&i8042_lock, flags);
- return ret;
+ return 0;
}
EXPORT_SYMBOL(i8042_remove_filter);
@@ -271,28 +255,22 @@ static int i8042_wait_write(void)
static int i8042_flush(void)
{
- unsigned long flags;
unsigned char data, str;
int count = 0;
- int retval = 0;
- spin_lock_irqsave(&i8042_lock, flags);
+ guard(spinlock_irqsave)(&i8042_lock);
while ((str = i8042_read_status()) & I8042_STR_OBF) {
- if (count++ < I8042_BUFFER_SIZE) {
- udelay(50);
- data = i8042_read_data();
- dbg("%02x <- i8042 (flush, %s)\n",
- data, str & I8042_STR_AUXDATA ? "aux" : "kbd");
- } else {
- retval = -EIO;
- break;
- }
- }
+ if (count++ >= I8042_BUFFER_SIZE)
+ return -EIO;
- spin_unlock_irqrestore(&i8042_lock, flags);
+ udelay(50);
+ data = i8042_read_data();
+ dbg("%02x <- i8042 (flush, %s)\n",
+ data, str & I8042_STR_AUXDATA ? "aux" : "kbd");
+ }
- return retval;
+ return 0;
}
/*
@@ -349,17 +327,12 @@ static int __i8042_command(unsigned char *param, int
command)
int i8042_command(unsigned char *param, int command)
{
- unsigned long flags;
- int retval;
-
if (!i8042_present)
return -1;
- spin_lock_irqsave(&i8042_lock, flags);
- retval = __i8042_command(param, command);
- spin_unlock_irqrestore(&i8042_lock, flags);
+ guard(spinlock_irqsave)(&i8042_lock);
- return retval;
+ return __i8042_command(param, command);
}
EXPORT_SYMBOL(i8042_command);
@@ -369,19 +342,18 @@ EXPORT_SYMBOL(i8042_command);
static int i8042_kbd_write(struct serio *port, unsigned char c)
{
- unsigned long flags;
- int retval = 0;
+ int error;
- spin_lock_irqsave(&i8042_lock, flags);
+ guard(spinlock_irqsave)(&i8042_lock);
- if (!(retval = i8042_wait_write())) {
- dbg("%02x -> i8042 (kbd-data)\n", c);
- i8042_write_data(c);
- }
+ error = i8042_wait_write();
+ if (error)
+ return error;
- spin_unlock_irqrestore(&i8042_lock, flags);
+ dbg("%02x -> i8042 (kbd-data)\n", c);
+ i8042_write_data(c);
- return retval;
+ return 0;
}
/*
@@ -460,9 +432,8 @@ static int i8042_start(struct serio *serio)
device_set_wakeup_enable(&serio->dev, true);
}
- spin_lock_irq(&i8042_lock);
+ guard(spinlock_irq)(&i8042_lock);
port->exists = true;
- spin_unlock_irq(&i8042_lock);
return 0;
}
@@ -476,10 +447,10 @@ static void i8042_stop(struct serio *serio)
{
struct i8042_port *port = serio->port_data;
- spin_lock_irq(&i8042_lock);
- port->exists = false;
- port->serio = NULL;
- spin_unlock_irq(&i8042_lock);
+ scoped_guard(spinlock_irq, &i8042_lock) {
+ port->exists = false;
+ port->serio = NULL;
+ }
/*
* We need to make sure that interrupt handler finishes using
@@ -583,45 +554,41 @@ static bool i8042_handle_data(int irq)
{
struct i8042_port *port;
struct serio *serio;
- unsigned long flags;
unsigned char str, data;
unsigned int dfl;
unsigned int port_no;
bool filtered;
- spin_lock_irqsave(&i8042_lock, flags);
-
- str = i8042_read_status();
- if (unlikely(~str & I8042_STR_OBF)) {
- spin_unlock_irqrestore(&i8042_lock, flags);
- return false;
- }
-
- data = i8042_read_data();
+ scoped_guard(spinlock_irqsave, &i8042_lock) {
+ str = i8042_read_status();
+ if (unlikely(~str & I8042_STR_OBF))
+ return false;
- if (i8042_mux_present && (str & I8042_STR_AUXDATA)) {
- port_no = i8042_handle_mux(str, &data, &dfl);
- } else {
+ data = i8042_read_data();
- dfl = (str & I8042_STR_PARITY) ? SERIO_PARITY : 0;
- if ((str & I8042_STR_TIMEOUT) && !i8042_notimeout)
- dfl |= SERIO_TIMEOUT;
+ if (i8042_mux_present && (str & I8042_STR_AUXDATA)) {
+ port_no = i8042_handle_mux(str, &data, &dfl);
+ } else {
- port_no = (str & I8042_STR_AUXDATA) ?
- I8042_AUX_PORT_NO : I8042_KBD_PORT_NO;
- }
+ dfl = (str & I8042_STR_PARITY) ? SERIO_PARITY : 0;
+ if ((str & I8042_STR_TIMEOUT) && !i8042_notimeout)
+ dfl |= SERIO_TIMEOUT;
- port = &i8042_ports[port_no];
- serio = port->exists ? port->serio : NULL;
+ port_no = (str & I8042_STR_AUXDATA) ?
+ I8042_AUX_PORT_NO : I8042_KBD_PORT_NO;
+ }
- filter_dbg(port->driver_bound, data, "<- i8042 (interrupt, %d,
%d%s%s)\n",
- port_no, irq,
- dfl & SERIO_PARITY ? ", bad parity" : "",
- dfl & SERIO_TIMEOUT ? ", timeout" : "");
+ port = &i8042_ports[port_no];
+ serio = port->exists ? port->serio : NULL;
- filtered = i8042_filter(data, str, serio);
+ filter_dbg(port->driver_bound,
+ data, "<- i8042 (interrupt, %d, %d%s%s)\n",
+ port_no, irq,
+ dfl & SERIO_PARITY ? ", bad parity" : "",
+ dfl & SERIO_TIMEOUT ? ", timeout" : "");
- spin_unlock_irqrestore(&i8042_lock, flags);
+ filtered = i8042_filter(data, str, serio);
+ }
if (likely(serio && !filtered))
serio_interrupt(serio, data, dfl);
@@ -779,24 +746,22 @@ static bool i8042_irq_being_tested;
static irqreturn_t i8042_aux_test_irq(int irq, void *dev_id)
{
- unsigned long flags;
unsigned char str, data;
- int ret = 0;
- spin_lock_irqsave(&i8042_lock, flags);
+ guard(spinlock_irqsave)(&i8042_lock);
+
str = i8042_read_status();
- if (str & I8042_STR_OBF) {
- data = i8042_read_data();
- dbg("%02x <- i8042 (aux_test_irq, %s)\n",
- data, str & I8042_STR_AUXDATA ? "aux" : "kbd");
- if (i8042_irq_being_tested &&
- data == 0xa5 && (str & I8042_STR_AUXDATA))
- complete(&i8042_aux_irq_delivered);
- ret = 1;
- }
- spin_unlock_irqrestore(&i8042_lock, flags);
+ if (!(str & I8042_STR_OBF))
+ return IRQ_NONE;
+
+ data = i8042_read_data();
+ dbg("%02x <- i8042 (aux_test_irq, %s)\n",
+ data, str & I8042_STR_AUXDATA ? "aux" : "kbd");
+
+ if (i8042_irq_being_tested && data == 0xa5 && (str & I8042_STR_AUXDATA))
+ complete(&i8042_aux_irq_delivered);
- return IRQ_RETVAL(ret);
+ return IRQ_HANDLED;
}
/*
@@ -837,7 +802,6 @@ static int i8042_check_aux(void)
int retval = -1;
bool irq_registered = false;
bool aux_loop_broken = false;
- unsigned long flags;
unsigned char param;
/*
@@ -921,18 +885,15 @@ static int i8042_check_aux(void)
if (i8042_enable_aux_port())
goto out;
- spin_lock_irqsave(&i8042_lock, flags);
-
- init_completion(&i8042_aux_irq_delivered);
- i8042_irq_being_tested = true;
-
- param = 0xa5;
- retval = __i8042_command(¶m, I8042_CMD_AUX_LOOP & 0xf0ff);
-
- spin_unlock_irqrestore(&i8042_lock, flags);
+ scoped_guard(spinlock_irqsave, &i8042_lock) {
+ init_completion(&i8042_aux_irq_delivered);
+ i8042_irq_being_tested = true;
- if (retval)
- goto out;
+ param = 0xa5;
+ retval = __i8042_command(¶m, I8042_CMD_AUX_LOOP & 0xf0ff);
+ if (retval)
+ goto out;
+ }
if (wait_for_completion_timeout(&i8042_aux_irq_delivered,
msecs_to_jiffies(250)) == 0) {
@@ -1020,7 +981,6 @@ static int i8042_controller_selftest(void)
static int i8042_controller_init(void)
{
- unsigned long flags;
int n = 0;
unsigned char ctr[2];
@@ -1057,14 +1017,14 @@ static int i8042_controller_init(void)
* Handle keylock.
*/
- spin_lock_irqsave(&i8042_lock, flags);
- if (~i8042_read_status() & I8042_STR_KEYLOCK) {
- if (i8042_unlock)
- i8042_ctr |= I8042_CTR_IGNKEYLOCK;
- else
- pr_warn("Warning: Keylock active\n");
+ scoped_guard(spinlock_irqsave, &i8042_lock) {
+ if (~i8042_read_status() & I8042_STR_KEYLOCK) {
+ if (i8042_unlock)
+ i8042_ctr |= I8042_CTR_IGNKEYLOCK;
+ else
+ pr_warn("Warning: Keylock active\n");
+ }
}
- spin_unlock_irqrestore(&i8042_lock, flags);
/*
* If the chip is configured into nontranslated mode by the BIOS, don't
--
2.46.0.469.g59c65b2a67-goog
