From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Antonino A. Daplas" Subject: Re: scrollmode selection problem Date: Tue, 13 Dec 2005 08:36:30 +0800 Message-ID: <439E178E.9070208@gmail.com> References: <439DB5A3.9050205@t-online.de> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1Ely9n-0004qF-A1 for linux-fbdev-devel@lists.sourceforge.net; Mon, 12 Dec 2005 16:36:39 -0800 Received: from zproxy.gmail.com ([64.233.162.198]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1Ely9m-0004eq-59 for linux-fbdev-devel@lists.sourceforge.net; Mon, 12 Dec 2005 16:36:39 -0800 Received: by zproxy.gmail.com with SMTP id s18so1690234nze for ; Mon, 12 Dec 2005 16:36:37 -0800 (PST) In-Reply-To: <439DB5A3.9050205@t-online.de> Sender: linux-fbdev-devel-admin@lists.sourceforge.net Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="iso-8859-1" To: linux-fbdev-devel@lists.sourceforge.net Cc: Knut Petersen Knut Petersen wrote: > Have a look at the following problem: >=20 > framebuffer memory size is 8MB > xres is 800, yres is 600, bpp is 8. > xres_virtual is 1024, yres_virtual is 8192. > font dimensions 8x16 >=20 > check_var() and set_par() are called, set_par() decides that ywrap > scrolling is possible and sets FBINFO_HWACCEL_YWRAP. >=20 > Well, that decision is _wrong_ as 600/16 results in a 37 line display > height, 8 pixel lines at the bottom are unused. But they are displayed, > and obviously they contain garbage as YWRAP scrolling is selected by > updatescrollmode(). I agree. >=20 > As the driver does know nothing about fonts, the obvious place to > change is updatescrollmode(). >=20 > int good_wrap =3D (cap & FBINFO_HWACCEL_YWRAP) && > divides(ywrap, vc->vc_font.height) && > divides(vc->vc_font.height, vyres) && > divides(vc->vc_font.height, yres); >=20 > would be a solution, but I don=B4t like it. There is no real reason tha= t It's a solution, and the correct one with the current code. > ywrap > scrolling should be disallowed when divides(vc->vc_font.height, vyres) > or divides(vc->vc_font.height, yres) are false ... only limitations of = the > fbcon scrolling code. >=20 > Has someone already written code to remove that limitation? None that I know of. Unfortunately, there's only a sprinkling of hardware that supports ywrap, so you're the best bet to do that (hint, hint :-)=20 Tony ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log fi= les for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=3D7637&alloc_id=3D16865&op=3Dclick