Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753458AbZGND45 (ORCPT ); Mon, 13 Jul 2009 23:56:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753350AbZGND45 (ORCPT ); Mon, 13 Jul 2009 23:56:57 -0400 Received: from mail-gx0-f213.google.com ([209.85.217.213]:36942 "EHLO mail-gx0-f213.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753351AbZGND44 convert rfc822-to-8bit (ORCPT ); Mon, 13 Jul 2009 23:56:56 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=ShmAt/WD84IaODIOjK9fpSgoUYG5vhrYmbuCWTILyKv3aHpAWqzqIC2HWjOHpLUfDu tba1Fh7mvrQql0j4/UVee5nAm6HltAT3nj+6V1WwCUeWv/0PzUG91/ihzN8bTt4+IpwL OvwCv3hdOBHmZY/Y0xK/rv9c6xGcYKB0McvaU= MIME-Version: 1.0 In-Reply-To: <20090714034353.GA1280@lilem.mirepesht> References: <20090713151709.GA1297@lilem.mirepesht> <20090713084058.547e88f0@infradead.org> <20090713162559.GA1279@lilem.mirepesht> <21d7e9970907131746q4f1a34efw9d3e6efaa78aea34@mail.gmail.com> <20090714034353.GA1280@lilem.mirepesht> Date: Tue, 14 Jul 2009 13:56:55 +1000 Message-ID: <21d7e9970907132056i1dd2eefbn290cb9ad8d318706@mail.gmail.com> Subject: Re: [PATCH 0/2] fbdev: add fillrect and copyarea ioctls From: Dave Airlie To: Ali Gholami Rudi Cc: Arjan van de Ven , fbdev , Andrew Morton , Andrea Righi , Krzysztof Helt , Greg Kroah-Hartman , Geert Uytterhoeven , Philippe De Muyter , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2170 Lines: 48 On Tue, Jul 14, 2009 at 1:43 PM, Ali Gholami Rudi wrote: > Dave Airlie wrote: >> On Tue, Jul 14, 2009 at 2:25 AM, Ali Gholami Rudi wrote: >> > Arjan van de Ven wrote: >> >> can we turn this around, is there a reason to add them? >> >> or in other words, how / where would these be used ? >> > >> > User-space programs that use framebuffer directly can use them. ?I was >> > writing a simple framebuffer virtual terminal (using libfreetype for >> > fonts; like fbterm); scrolling and painting boxes would be faster if >> > there was someway of using hardware accelerated operations. ?I think >> > other similar programs can benefit, too. >> >> The general opinion is we should keep acceleration in userspace if at >> all possible. > > I see. ?The line between user- and kernel-space for graphic applications > is very blurred to me :-) > >> Not all hw can implement these usefully in the kernel, directfb > > AFAICT, many major ones like intelfb, radeonfb and nv implement them and > those that can't, use a software implementation. ?You mean they are > unreliable or that there is little performance improvement because of > the way those operations are implemented in the kernel? Generally newer consumer HW can't implement a simple blit without using the 3D engine which requires a large amount of state to be sent to the device. Keeping the state encoding and stuff out of the kernel and in userspace is generally seen as the right thing to do. >> already does some >> things for this. > > Sometime ago I did try running directfb on a radeon r300 and it failed. > I didn't try hard to see what's wrong but I got the impression that > userspace apps are not good at using the hardware directly. directfb has hw accel for different cards, really porting the code out of the kernel for the cards you are interested in would probably benefit more. Dave. -- 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/