7 files changed, 117 insertions, 12 deletions

diff --git a/drivers/input/mouse/sentelic.c b/drivers/input/mouse/sentelic.c
index 84e2fc04d11b..f84cbd97c884 100644
--- a/drivers/input/mouse/sentelic.c
+++ b/drivers/input/mouse/sentelic.c
@@ -92,7 +92,8 @@ static int fsp_reg_read(struct psmouse *psmouse, int reg_addr, int *reg_val)
          */
         ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE);
         psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
-        mutex_lock(&ps2dev->cmd_mutex);
+
+        ps2_begin_command(ps2dev);
 
         if (ps2_sendbyte(ps2dev, 0xf3, FSP_CMD_TIMEOUT) < 0)
                 goto out;
@@ -126,7 +127,7 @@ static int fsp_reg_read(struct psmouse *psmouse, int reg_addr, int *reg_val)
         rc = 0;
 
  out:
-        mutex_unlock(&ps2dev->cmd_mutex);
+        ps2_end_command(ps2dev);
         ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE);
         psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
         dev_dbg(&ps2dev->serio->dev, "READ REG: 0x%02x is 0x%02x (rc = %d)\n",
@@ -140,7 +141,7 @@ static int fsp_reg_write(struct psmouse *psmouse, int reg_addr, int reg_val)
         unsigned char v;
         int rc = -1;
 
-        mutex_lock(&ps2dev->cmd_mutex);
+        ps2_begin_command(ps2dev);
 
         if (ps2_sendbyte(ps2dev, 0xf3, FSP_CMD_TIMEOUT) < 0)
                 goto out;
@@ -179,7 +180,7 @@ static int fsp_reg_write(struct psmouse *psmouse, int reg_addr, int reg_val)
         rc = 0;
 
  out:
-        mutex_unlock(&ps2dev->cmd_mutex);
+        ps2_end_command(ps2dev);
         dev_dbg(&ps2dev->serio->dev, "WRITE REG: 0x%02x to 0x%02x (rc = %d)\n",
                 reg_addr, reg_val, rc);
         return rc;
@@ -214,7 +215,8 @@ static int fsp_page_reg_read(struct psmouse *psmouse, int *reg_val)
 
         ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE);
         psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
-        mutex_lock(&ps2dev->cmd_mutex);
+
+        ps2_begin_command(ps2dev);
 
         if (ps2_sendbyte(ps2dev, 0xf3, FSP_CMD_TIMEOUT) < 0)
                 goto out;
@@ -236,7 +238,7 @@ static int fsp_page_reg_read(struct psmouse *psmouse, int *reg_val)
         rc = 0;
 
  out:
-        mutex_unlock(&ps2dev->cmd_mutex);
+        ps2_end_command(ps2dev);
         ps2_command(ps2dev, NULL, PSMOUSE_CMD_ENABLE);
         psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
         dev_dbg(&ps2dev->serio->dev, "READ PAGE REG: 0x%02x (rc = %d)\n",
@@ -250,7 +252,7 @@ static int fsp_page_reg_write(struct psmouse *psmouse, int reg_val)
         unsigned char v;
         int rc = -1;
 
-        mutex_lock(&ps2dev->cmd_mutex);
+        ps2_begin_command(ps2dev);
 
         if (ps2_sendbyte(ps2dev, 0xf3, FSP_CMD_TIMEOUT) < 0)
                 goto out;
@@ -275,7 +277,7 @@ static int fsp_page_reg_write(struct psmouse *psmouse, int reg_val)
         rc = 0;
 
  out:
-        mutex_unlock(&ps2dev->cmd_mutex);
+        ps2_end_command(ps2dev);
         dev_dbg(&ps2dev->serio->dev, "WRITE PAGE REG: to 0x%02x (rc = %d)\n",
                 reg_val, rc);
         return rc;
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index eb3ff94af58c..bc56e52b945f 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -87,8 +87,22 @@ static bool i8042_bypass_aux_irq_test;
 
 #include "i8042.h"
 
+/*
+ * i8042_lock protects serialization between i8042_command and
+ * the interrupt handler.
+ */
 static DEFINE_SPINLOCK(i8042_lock);
 
+/*
+ * Writers to AUX and KBD ports as well as users issuing i8042_command
+ * directly should acquire i8042_mutex (by means of calling
+ * i8042_lock_chip() and i8042_unlock_ship() helpers) to ensure that
+ * they do not disturb each other (unfortunately in many i8042
+ * implementations write to one of the ports will immediately abort
+ * command that is being processed by another port).
+ */
+static DEFINE_MUTEX(i8042_mutex);
+
 struct i8042_port {
         struct serio *serio;
         int irq;
@@ -113,6 +127,18 @@ static struct platform_device *i8042_platform_device;
 
 static irqreturn_t i8042_interrupt(int irq, void *dev_id);
 
+void i8042_lock_chip(void)
+{
+        mutex_lock(&i8042_mutex);
+}
+EXPORT_SYMBOL(i8042_lock_chip);
+
+void i8042_unlock_chip(void)
+{
+        mutex_unlock(&i8042_mutex);
+}
+EXPORT_SYMBOL(i8042_unlock_chip);
+
 /*
  * The i8042_wait_read() and i8042_wait_write functions wait for the i8042 to
  * be ready for reading values from it / writing values to it.
@@ -1161,6 +1187,21 @@ static void __devexit i8042_unregister_ports(void)
         }
 }
 
+/*
+ * Checks whether port belongs to i8042 controller.
+ */
+bool i8042_check_port_owner(const struct serio *port)
+{
+        int i;
+
+        for (i = 0; i < I8042_NUM_PORTS; i++)
+                if (i8042_ports[i].serio == port)
+                        return true;
+
+        return false;
+}
+EXPORT_SYMBOL(i8042_check_port_owner);
+
 static void i8042_free_irqs(void)
 {
         if (i8042_aux_irq_registered)
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index 3a95b508bf27..769ba65a585a 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -17,6 +17,7 @@
 #include <linux/interrupt.h>
 #include <linux/input.h>
 #include <linux/serio.h>
+#include <linux/i8042.h>
 #include <linux/init.h>
 #include <linux/libps2.h>
 
@@ -54,6 +55,24 @@ int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout)
 }
 EXPORT_SYMBOL(ps2_sendbyte);
 
+void ps2_begin_command(struct ps2dev *ps2dev)
+{
+        mutex_lock(&ps2dev->cmd_mutex);
+
+        if (i8042_check_port_owner(ps2dev->serio))
+                i8042_lock_chip();
+}
+EXPORT_SYMBOL(ps2_begin_command);
+
+void ps2_end_command(struct ps2dev *ps2dev)
+{
+        if (i8042_check_port_owner(ps2dev->serio))
+                i8042_unlock_chip();
+
+        mutex_unlock(&ps2dev->cmd_mutex);
+}
+EXPORT_SYMBOL(ps2_end_command);
+
 /*
  * ps2_drain() waits for device to transmit requested number of bytes
  * and discards them.
@@ -66,7 +85,7 @@ void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout)
                 maxbytes = sizeof(ps2dev->cmdbuf);
         }
 
-        mutex_lock(&ps2dev->cmd_mutex);
+        ps2_begin_command(ps2dev);
 
         serio_pause_rx(ps2dev->serio);
         ps2dev->flags = PS2_FLAG_CMD;
@@ -76,7 +95,8 @@ void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout)
         wait_event_timeout(ps2dev->wait,
                            !(ps2dev->flags & PS2_FLAG_CMD),
                            msecs_to_jiffies(timeout));
-        mutex_unlock(&ps2dev->cmd_mutex);
+
+        ps2_end_command(ps2dev);
 }
 EXPORT_SYMBOL(ps2_drain);
 
@@ -237,9 +257,9 @@ int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
 {
         int rc;
 
-        mutex_lock(&ps2dev->cmd_mutex);
+        ps2_begin_command(ps2dev);
         rc = __ps2_command(ps2dev, param, command);
-        mutex_unlock(&ps2dev->cmd_mutex);
+        ps2_end_command(ps2dev);
 
         return rc;
 }
diff --git a/drivers/leds/leds-clevo-mail.c b/drivers/leds/leds-clevo-mail.c
index 1813c84ea5fc..f2242db54016 100644
--- a/drivers/leds/leds-clevo-mail.c
+++ b/drivers/leds/leds-clevo-mail.c
@@ -93,6 +93,8 @@ static struct dmi_system_id __initdata mail_led_whitelist[] = {
 static void clevo_mail_led_set(struct led_classdev *led_cdev,
                                 enum led_brightness value)
 {
+        i8042_lock_chip();
+
         if (value == LED_OFF)
                 i8042_command(NULL, CLEVO_MAIL_LED_OFF);
         else if (value <= LED_HALF)
@@ -100,6 +102,8 @@ static void clevo_mail_led_set(struct led_classdev *led_cdev,
         else
                 i8042_command(NULL, CLEVO_MAIL_LED_BLINK_1HZ);
 
+        i8042_unlock_chip();
+
 }
 
 static int clevo_mail_led_blink(struct led_classdev *led_cdev,
@@ -108,6 +112,8 @@ static int clevo_mail_led_blink(struct led_classdev *led_cdev,
 {
         int status = -EINVAL;
 
+        i8042_lock_chip();
+
         if (*delay_on == 0 /* ms */ && *delay_off == 0 /* ms */) {
                 /* Special case: the leds subsystem requested us to
                  * chose one user friendly blinking of the LED, and
@@ -135,6 +141,8 @@ static int clevo_mail_led_blink(struct led_classdev *led_cdev,
                        *delay_on, *delay_off);
         }
 
+        i8042_unlock_chip();
+
         return status;
 }
 
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index fb45f5ee8df1..454970d2d701 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -746,7 +746,9 @@ static acpi_status WMID_set_u32(u32 value, u32 cap, struct wmi_interface *iface)
                         return AE_BAD_PARAMETER;
                 if (quirks->mailled == 1) {
                         param = value ? 0x92 : 0x93;
+                        i8042_lock_chip();
                         i8042_command(&param, 0x1059);
+                        i8042_unlock_chip();
                         return 0;
                 }
                 break;
diff --git a/include/linux/i8042.h b/include/linux/i8042.h
index 7907a72403ee..60c3360ef6ad 100644
--- a/include/linux/i8042.h
+++ b/include/linux/i8042.h
@@ -7,6 +7,7 @@
  * the Free Software Foundation.
  */
 
+#include <linux/types.h>
 
 /*
  * Standard commands.
@@ -30,6 +31,35 @@
 #define I8042_CMD_MUX_PFX       0x0090
 #define I8042_CMD_MUX_SEND      0x1090
 
+struct serio;
+
+#if defined(CONFIG_SERIO_I8042) || defined(CONFIG_SERIO_I8042_MODULE)
+
+void i8042_lock_chip(void);
+void i8042_unlock_chip(void);
 int i8042_command(unsigned char *param, int command);
+bool i8042_check_port_owner(const struct serio *);
+
+#else
+
+void i8042_lock_chip(void)
+{
+}
+
+void i8042_unlock_chip(void)
+{
+}
+
+int i8042_command(unsigned char *param, int command)
+{
+        return -ENOSYS;
+}
+
+bool i8042_check_port_owner(const struct serio *serio)
+{
+        return false;
+}
+
+#endif
 
 #endif
diff --git a/include/linux/libps2.h b/include/linux/libps2.h
index fcf5fbe6a50c..79603a6c356f 100644
--- a/include/linux/libps2.h
+++ b/include/linux/libps2.h
@@ -44,6 +44,8 @@ struct ps2dev {
 void ps2_init(struct ps2dev *ps2dev, struct serio *serio);
 int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout);
 void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout);
+void ps2_begin_command(struct ps2dev *ps2dev);
+void ps2_end_command(struct ps2dev *ps2dev);
 int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command);
 int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command);
 int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data);