Re: [linux-sunxi] Re: [PATCH v3 1/4] dt-bindings: simplefb: Specify node location and handoff relate

On Thu, Nov 13, 2014 at 3:52 PM, Tomi Valkeinen [off-list ref] wrote:

On 13/11/14 16:46, Hans de Goede wrote:

quoted

Hi,

On 11/13/2014 03:28 PM, Tomi Valkeinen wrote:

quoted

On 13/11/14 15:34, Hans de Goede wrote:

quoted

+chosen {
+   framebuffer0: framebuffer@5fc00000 {
            compatible = "simple-framebuffer";
-           reg = <0x1d385000 (1600 * 1200 * 2)>;
+           reg = <0x5fc00000 (4096 * 1024)>;

Was there a reason for this change?

I changed the node name to match the new bindings text which
specifies that the node name must be framebuffer@<address>,
while at it I've taken a real world address range.

I assume you refer to the bit where the size of the reg property
is changed ? That indeed is not really necessary.

Yes, I meant the size of the reg prop. As this is an example, I think it
should be as clear as possible.

I guess a valid use case here is to set the size to larger-than-needed,
so that it gets preallocated and you don't need to worry about getting
the memory later when the system has already been running for a longer
time. But if that's the case in this example, I think it would be better
to describe it explicitly.

Besides, we already have a mechanism for that called /reserved-memory.
Any memory used by a framebuffer needs to be described in the reserved
map anyway, and that region can be made larger than the firmware
configured framebuffer.

g.