• Magnus Damm's avatar
    sm501fb: clear framebuffer memory and palette · b1230ee5
    Magnus Damm authored
    Avoid displaying garbage on unused framebuffers.  For most users a single
    framebuffer is used together with fbcon.  sm501fb supports two framebuffers
    where one often is assigned to fbcon and the other one is left unused during
    the boot.
    The problem here is that framebuffers not in use by fbcon happen to display
    garbage.  This can easily be solved by making sure that framebuffer memory and
    palette ram are cleared.
    The problem can be observed by using looking at the panel output (fb1) after
    booting the kernel with fbcon on crt (fb0).  This is the default
    configuration.  It's also possible to watch the garbage on the crt framebuffer
    by passing "fbcon=map:1" on the kernel cmdline.  This will assign fbcon to the
    panel (fb1) and leave the crt (fb0) unused.
    Signed-off-by: default avatarMagnus Damm <damm@igel.co.jp>
    Cc: "Antonino A. Daplas" <adaplas@pol.net>
    Cc: Paul Mundt <lethal@linux-sh.org>
    Cc: Ben Dooks <ben-linux@fluff.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>