Input: libps2 - additional locking for i8042 ports

The serio ports on i8042 are not completely isolated; while we provide
enough locking to ensure proper serialization when accessing control
and data registers AUX and KBD ports can still have an effect on each
other on PS/2 protocol level. The most prominent effect is that
issuing a command for the device connected to one port may cause
abort of the command currently executing by the device connected to
another port.

Since i8042 nor serio subsystem are not aware of the details of the
PS/2 protocol (length of the commands and their replies and so on) the
locking should be done on libps2 level by adding special handling when
we see that we are dealing with serio port on i8042.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 2 insertions, 0 deletions

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;