From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Date: Thu, 10 Dec 2009 19:55:39 +0000 Subject: Re: conflicts between fbcon and user-mode fbdev clients Message-Id: <10f740e80912101155uad00e1atc8a12fea3be3e5df@mail.gmail.com> List-Id: References: <480988180912091352v77fa9a12s5077b3211c13586b@mail.gmail.com> In-Reply-To: <480988180912091352v77fa9a12s5077b3211c13586b@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: linux-fbdev@vger.kernel.org On Thu, Dec 10, 2009 at 20:43, Bernie Thompson wrote: > On Thu, Dec 10, 2009 at 11:02 AM, James Simmons wrote: >> That shouldn't happen. In the xorg.conf do you have in the >> >> Option UseFBDev "True" > > That option appears to have no effect (have tried both ways).  Do you > know who parses it?  Couldn't find it in core xserver. > > The DisplayLink support is still very rough, but it's currently using > its own X server driver > (http://libdlo.freedesktop.org/wiki/xf86-driver-displaylink), which > has some IOCTLs to its framebuffer driver, including a mode setting > IOCTL. > > If the arbitration between fbdev clients is intended to happen at the > point of mode setting, rather than at open(), that would explain the > problem.  Are there any old posts or docs which describe how > arbitration is handled for the fbdev driver and multiple clients? Usually the X server locks the VT (virtual terminal) using an ioctl, and uses another ioctl to switch the VT to graphics mode, so fbcon will stop drawing to it. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds