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>
Export the i8042_command() function which manages the mutual
exclusion with the help of the i8042_lock spinlock. This allows
to access i8042 safely from other parts of the kernel.
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
