[PATCH -cirrus] Add a check for max_pitch values for GD5446 / FAUmachine

[Adam Jackson]

On Jan 14, 2011, at 5:50 PM, Bryce Harrington wrote:

> The GD 5446 uses 9 bits to store the pitch value, which then get shifted
> by 3 bits to the left in the graphic card. For the resolution of
> 1360x768 however, X sets the pitch to 1408, which hence results in an
> actual used pitch by the card of 128. As a result the screen is garbled.
> 
> GD 5446 with 4mb is pretty rare hardware but is simulated by FAUmachine.

qemu's emulated cirrus device is also a 5446 (well, when it's emulating a PCI
cirrus card and not an ISA cirrus card).  So I think my ack would depend on
whether this bug also exists in qemu.

- ajax