<div class="gmail_quote">2013/6/21 David Herrmann <<a href="mailto:dh.herrmann@gmail.com" target="_blank">dh.herrmann@gmail.com</a>> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hi <div><div class="h5"> On Fri, Jun 21, 2013 at 11:43 AM, Marc Chalain <<a href="mailto:marc.chalain@gmail.com">marc.chalain@gmail.com</a>> wrote: > > 2013/6/21 David Herrmann <<a href="mailto:dh.herrmann@gmail.com">dh.herrmann@gmail.com</a>> >> >> Hi >> >> On Fri, Jun 21, 2013 at 10:49 AM, mchalain [<a href="mailto:marc.chalain@gmail.com">marc.chalain@gmail.com</a>] >> <<a href="mailto:marc.chalain@gmail.com">marc.chalain@gmail.com</a>> wrote: >> > From: mchalain <<a href="mailto:marc.chalain@gmail.com">marc.chalain@gmail.com</a>> >> > >> > it initializes varinfo.yoffset. varinfo.yoffset has to >> > point on the beginning of the video memory. >> > The card uses this value to push on the screen a part of >> > the video memory when this one is larger than the screen. >> > >> > --- >> > weston/src/compositor-fbdev.c | 6 ++++++ >> > 1 file changed, 6 insertions(+) >> > >> > diff --git a/weston/src/compositor-fbdev.c >> > b/weston/src/compositor-fbdev.c >> > index adfb67a..d2aee9b 100644 >> > --- a/weston/src/compositor-fbdev.c >> > +++ b/weston/src/compositor-fbdev.c >> > @@ -368,6 +368,11 @@ fbdev_query_screen_info(struct fbdev_output >> > *output, int fd, >> > return -1; >> > } >> > >> > + if (varinfo.yoffset != 0) { >> > + varinfo.yoffset = 0; >> > + if (ioctl(fd, FBIOPAN_DISPLAY, &varinfo) < 0) >> > + return -1; >> > + } >> >> Why do you need this? It's unnecessary. We call FBIOPUT_VSCREENINFO >> after fbdev_query_screen_info(), anyway. Furthermore, not all drivers >> support panning even though the yoffset may be non-zero (you need >> FBIOPUT_VSCREENINFO then). >> >> I think you can just drop this here but keep the yoffset=0 below. >> > > where do you use FBIOPUT_VSCREENINFO ? I only find inside > fbdev_set_screen_info but this function is called only when the output is > reenable not at the startup. </div></div>My bad! But still, you now call FBIOPAN_DISPLAY on _every_ fbdev_query_screen_info() while it is only needed during initial setup as VT_ENTER calls fbdev_set_screen_info(), anyway. So instead, I'd recommend to just call fbdev_set_screen_info() during initial setup as well. <div class="im"> </div></blockquote><div> No I call FBIOPAN_DISPLAY only at startup after yoffset is set to 0 </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="im"> > It seems strange that FBIOPAN_DISPLAY is not supported by some devices. I > used this one to not set all the varinfo on the device and to be faster. </div>See ./drivers/video/fbmem.c fb_pan_display(). Trivial fbdev drivers might not support it, but user-space can still set the offset via FBIOPUT_VSCREENINFO. If you want, you can call FBIOPAN_DISPLAY and if it fails, you use FBIOPUT_VSCREENINFO. <div class="im"> </div></blockquote><div>I read the yoffset hasn't to be null in FB_VMODE_YWRAP . But yoffset is only used for panning. It's useless to set it if it doesn't use (fbmem.c uses yoffset only for panning in your example too) </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im"> > If yoffset may be non-zero this backend shouldn't work this kind of devices > and we have to change the painting functions. </div>yoffset=0; is the correct thing to do. Cheers David <div class="HOEnZb"><div class="h5"> >> > return 1; >> > } >> > >> > @@ -404,6 +409,7 @@ fbdev_set_screen_info(struct fbdev_output *output, >> > int fd, >> > varinfo.blue.length = 8; >> > varinfo.blue.msb_right = 0; >> > >> > + varinfo.yoffset = 0; >> >> Yep, this is definitely needed. >> >> Regards >> David >> >> > /* Set the device's screen information. */ >> > if (ioctl(fd, FBIOPUT_VSCREENINFO, &varinfo) < 0) { >> > return -1; >> > -- >> > 1.7.9.5 >> > >> > _______________________________________________ >> > wayland-devel mailing list >> > <a href="mailto:wayland-devel@lists.freedesktop.org">wayland-devel@lists.freedesktop.org</a> >> > <a href="http://lists.freedesktop.org/mailman/listinfo/wayland-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/wayland-devel</a> > > </div></div></blockquote></div>