<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 12:05 PM, 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 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. >> >> 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. >> > > No I call FBIOPAN_DISPLAY only at startup after yoffset is set to 0 </div></div>You call it everytime yoffset isn't 0. So if you VT_LEAVE, another application changes the yoffset for whatever reason and we VT_ENTER, you will end up calling FBIOPAN_DISPLAY again followed by fbdev_set_screen_info() if the screen-info changed. Don't expect applications on other VTs to behave as expected. They may do anything! They may even use some acceleration which we in weston aren't aware of. <div class="im"> </div></blockquote><div>If another application set yoffset, with VT_ENTER we pass inside fbdev_set_screen_info and yoffset is set to 0. After fbdev_set_screen_info is buggy and this patch is not a bugfix... the bug is you set varinfo.bits_per_pixel with a value that could be different of 32 and after you set the colors as A8R8G8B8 ... I don't want to use it, because I can't check all cases of this function, my card is too simple... </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. >> >> 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. >> > 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>A driver may not support FBIOPAN_DISPLAY but still support panning via FBIOPUT_VSCREENINFO. If any framebuffer parameter change requires a full modeset, there is no reason to support FBIOPAN_DISPLAY. But panning may still be supported via yoffset and FBIOPUT_VSCREENINFO. </blockquote><div>You tell that kernel bug must be corrected by kernel developers in the thread about SYN_DROPPED and now you tell me that we have to check that the driver should not be completed ??? I don't understand the need to add useless code. I will change FBIOPAN_DISPLAY by FBIOPUT_VSCREENINFO but it's only to make you happy. </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Cheers David </blockquote></div>