linux-mips
[Top] [All Lists]

Re: CCA4 mapping

To: linux-mips@linux-mips.org
Subject: Re: CCA4 mapping
From: Hauke Goos-Habermann <haukeh@pc-kiel.de>
Date: Mon, 30 May 2005 14:05:55 +0200
In-reply-to: <530c77f53c1c8706d6fd75a07ad091ca@embeddedalley.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <200505261520.34985.haukeh@pc-kiel.de> <530c77f53c1c8706d6fd75a07ad091ca@embeddedalley.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: KMail/1.7.2
Am Donnerstag, 26. Mai 2005 21:39 schrieb Dan Malek:
> On May 26, 2005, at 9:20 AM, Hauke Goos-Habermann wrote:
> > Does anybody have an idea how to make the CCA4 mapping?
>
> In the mmap() entry for the driver:
>
>       pgprot_val(vma->vm_page_prot) |= (4 << 9);      /* CCA4 */
This is what I tried earlier. It doesn't speed up the driver. Enabling the 
caching with setting the CMEM register doesn't help too.

> or, whatever is appropriate.  This will only work from a user
> application (like X-Windows) that mmaps() the driver, you
> aren't going to get a kernel mapped space this way without
> some special VM space hacking.
I think that's what I need. The normal framebuffer driver is very slow and I 
need a faster and direct access to the video memory.

That's why I tried to use the add_wired_entry function. There I can enable the 
CCA4 and make a wired entry. But this doesn't work either:

add_wired_entry((0x00800000 >> 2) | 0x0027, (0x00900000 >> 2) | 0x0027, 
0x30000000 | 0x0027, 0x01ffe000);
add_wired_entry((0x00a00000 >> 2) | 0x0027, (0x00a00000 >> 2) | 0x0027, 
0x32000000 | 0x0027, 0x01ffe000);

The graphic card is a FUJITSU MB86290. Does anybody have experiences with this 
device?

Does anybody have an idea how to make the access to the video memory faster?

> Thanks.
>
>       -- Dan
Cu Hauke

<Prev in Thread] Current Thread [Next in Thread>