Messages in this thread | | | Date | Mon, 30 Oct 2006 14:35:01 +0100 | From | "Miguel Ojeda" <> | Subject | Re: [PATCH 2.6.19-rc1 full] drivers: add LCD support |
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On 10/30/06, Franck Bui-Huu <vagabon.xyz@gmail.com> wrote: > Miguel Ojeda wrote: > > > > Sorry, I meant: You can't mmap a RAM address using functions like the > > usual remap_pfn_range (as such functions doesn't like physical RAM > > addresses, they want I/O ports for example, like 0x378). So, you can't > > use smem_start. You need to code your own mmap & nopage function. (It > > is explained in LDD3 very well). > > > > well I must admit that I don't understand why... I suppose you refered > to that section in ldd3: > > An interesting limitation of remap_pfn_range is that it gives > access only to reserved pages and physical addresses above the > top of physical memory. > > I take a quick look at the implementation of remap_pfn_range() and > there's no such limitation I can see (fortunately). > > Franck >
Read further ;-)
"Therefore, remap_pfn_range won't allow you to remap conventional addresses, which include the ones you obtain by calling get_free_pages"
Because of such limitation, they teach you to remap RAM in other ways. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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