The sysrq input handler should be attached to the input device which has
a left alt key.
On 32-bit kernels, some input devices which has a left alt key cannot
attach sysrq handler. Because the keybit bitmap in struct input_device_id
for sysrq is not correctly initialized. KEY_LEFTALT is 56 which is
greater than BITS_PER_LONG on 32-bit kernels.
I found this problem when using a matrix keypad device which defines
a KEY_LEFTALT (56) but doesn't have a KEY_O (24 == 56%32).
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
802c03881f