Re: [PATCH] Do set var even if no fb_check_var() provided.
From: Michel Dänzer <hidden>
Date: 2008-08-28 06:53:44
On Wed, 2008-08-27 at 23:49 +0200, Helge Deller wrote:
Geert Uytterhoeven wrote:quoted
On Wed, 27 Aug 2008, Takashi Yoshii wrote:quoted
The behavior of FBIOSET_VSCREENINFO seems to be weired on FB which does not provides fbops->fb_check_var. It doesn't set anything, but gets info->var instead, and returns no error. It is just same as FBIOGET_VSCREENINFO does. IMHO, this should be one of the following candidates, 1. set var without check. 2. do nothing but return error (setting var is not supported). or 3. it's a bug (fb_check_var should always be provided). The patch at the bottom implements "1". Because I don't know API specification, nor the history of the code, I would like people who knows well to discuss this.If the driver doesn't provide a fb_check_var(), it means it cannot change video mode. Hence this rules out #1. #2 is not acceptable, as it will break existing applications. It's also incorrect, as FBIOPUT_VSCREENINFO should succeed for supported modes. For unsupported modes, the mode should be rounded up to a supported mode, if possible. In the case of drivers that support one fixed mode only, this rounding up is relaxed to `rounding' to the sole supported mode. #3 is also wrong, as fb_check_var() has been deliberately made optional to simplify drivers that support one fixed mode only. Conclusion: nothing should be changed?I'm not sure. On parisc we just stumbled over exactly this problem where I think Takashi's proposal "1." is probably the right solution. Please see my Xorg bugzilla entry: https://bugs.freedesktop.org/show_bug.cgi?id=17153
I believe (bugs.freedesktop.org is currently down) that's currently waiting for information from you. Namely, have you tried not specifying a Modes line in the xorg.conf SubSection "Display"? I think the Xorg fbdev driver should come up with the currently active mode in that case. If that doesn't work, please attach the corresponding Xorg.0.log to the bug report once bugzilla is back online. -- Earthling Michel Dänzer | http://tungstengraphics.com Libre software enthusiast | Debian, X and DRI developer ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Linux-fbdev-devel mailing list Linux-fbdev-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-fbdev-devel