From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ondrej Zajicek Subject: Re: framebuffer general questions Date: Fri, 13 Nov 2009 21:08:00 +0100 Message-ID: <20091113200759.GA5379@localhost> References: <1023.2945-18821-2123977998-1258121508@seznam.cz> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7469815326049442991==" Return-path: Received: from sfi-mx-3.v28.ch3.sourceforge.com ([172.29.28.123] helo=mx.sourceforge.net) by 335xhf1.ch3.sourceforge.com with esmtp (Exim 4.69) (envelope-from ) id 1N92h6-00014S-8I for linux-fbdev-devel@lists.sourceforge.net; Fri, 13 Nov 2009 20:24:32 +0000 Received: from gateway.crfreenet.org ([81.92.146.254] helo=mail.crfreenet.org) by 3b2kzd1.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.69) id 1N92h2-0004Ob-8A for linux-fbdev-devel@lists.sourceforge.net; Fri, 13 Nov 2009 20:24:32 +0000 In-Reply-To: <1023.2945-18821-2123977998-1258121508@seznam.cz> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: =?utf-8?B?UmVuw6kgS29sYcWZw61r?= Cc: linux-fbdev-devel@lists.sourceforge.net --===============7469815326049442991== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="G4iJoqBmSsgzjUCe" Content-Disposition: inline --G4iJoqBmSsgzjUCe Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Nov 13, 2009 at 03:11:48PM +0100, Ren=C3=A9 Kola=C5=99=C3=ADk wrote: > Hi >=20 > i am trying to customize framebuffer drivers and i have some questions... >=20 > Please can you give me an advice?=20 >=20 > 1) If I define my own imageblit function, how do I call it? Or is it call= ed automatically? It is called automatically (if it is registered in fb_ops structure) =66rom kernel console. It is not possible to call it from userspace. > 2) I have gpu connected via pci to cpu. I did mmap and have > framebuffer mapped in for example "uchar * data". I have loop and > iterating through some pixel data and do data[i] =3D pixel[i]. Does this > lead to transmitting via PCI in style - transmit byte ... end ... > transmit byte ... end ... etc? Probably yes, perhaps there is some write combining according to MTRR registers. > 3)what is the difference bethween mmap framebuffer and write to mapped > pointer and calling write() to descriptor previously obtained by open()? The first variant is much faster - video RAM is directly mapped to userspac= e=20 address space, therefore there is no kernel interaction during writes (in usual fbdev drivers). --=20 Elen sila lumenn' omentielvo Ondrej 'SanTiago' Zajicek (email: santiago@crfreenet.org) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so." --G4iJoqBmSsgzjUCe Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkr9vJ8ACgkQw1GB2RHercOeXQCeLi8UQrhk/hkB0v+OdwK4NqHf oF4An09SLS3EUYoLJhHcbbhHw4BT9DAb =aWxd -----END PGP SIGNATURE----- --G4iJoqBmSsgzjUCe-- --===============7469815326049442991== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july --===============7469815326049442991== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Linux-fbdev-devel mailing list Linux-fbdev-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-fbdev-devel --===============7469815326049442991==--