dma_alloc_writecombine() and MAX_ORDER
From: Russell King - ARM Linux <hidden>
Date: 2011-05-03 08:44:37
On Tue, May 03, 2011 at 08:25:32AM +0200, Michael Hunold wrote:
Hello Russell, on 04/29/2011 04:27 PM Russell King - ARM Linux said the following:quoted
On Fri, Apr 29, 2011 at 02:50:37PM +0200, Michael Hunold wrote:quoted
quoted
Now I have a new panel with a higher resolution and more bits-per-pixel. I want to use double-buffering with DirectFB and so my framebuffer size exceeds 4Mb.quoted
You could try this patch. It steals the memory for the coherent and writecombine memory at boot time, so MAX_ORDER no longer comes into the problem. You may need to define CONSISTENT_WC_SIZE and CONSISTENT_DMA_SIZE appropriately to gain sufficient memory. Note that the sum of those two must be a multiple of 2MB, and individually must be a multiple of 1MB.I really want to try this patch out, but unfortunately, I don't know to which tree I can apply it to. :-(
You may need 516295e (ARM: pgtable: add pud-level code) from a later kernel as well then.