Comment # 1 on bug 107328 from Christian König

(In reply to Paul Menzel from comment #0)
> Is there a way to get rid of the for loop? Some memset equivalent?

At least not easily. 

The hardware is not initialized yet, so we have to writeback the GART table
using the CPU.

Depending on the size of the table (which in turn depends on installed system
memory) it can easily take even more than a second to do this.