By default, udlfb allocates a 2nd buffer to shadow what's across
the bus on the USB device. It can operate without this shadow,
but then it cannot tell which pixels have changed, and must send all.
Saves host memory, but worsens the USB 2.0 bus bottleneck.
This option allows users in very low memory situations (e.g.
bifferboard) to optionally turn off this shadow framebuffer.
Signed-off-by: Stuart Hopkins <stuart@linux-depot.com>
Signed-off-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
udlfb has undergone a fair bit of cleanup recently and is effectively at
the point where it can be liberated from staging purgatory and promoted
to a real driver.
The outstanding cleanups are all minor, with some of them dependent on
drivers/video headers, so these will be done incrementally from udlfb's
new home.
Requested-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>