[PATCH 4/6] libweston: fbdev: set fb device info upon the first run.

[Pekka Paalanen]

On Thu, 14 Sep 2017 23:08:51 -0400
nerdopolis <bluescreen_avenger at verizon.net> wrote:

> On Wednesday, September 6, 2017 8:17:21 AM EDT nerdopolis wrote:
> > This attempts to wake up secondary framebuffer devices
> > (/dev/fb1 and up) as usually these devices start powered off, and
> > the FBIOPUT_VSCREENINFO ioctl turns it on. This was tested on a
> > qemu system with the options:
> > 
> > -vga none -device VGA,id=video0 -device secondary-vga,id=video1 \
> > -device secondary-vga,id=video2
> > ---
> >  libweston/compositor-fbdev.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/libweston/compositor-fbdev.c b/libweston/compositor-fbdev.c
> > index b4f0685c..a9cc08be 100644
> > --- a/libweston/compositor-fbdev.c
> > +++ b/libweston/compositor-fbdev.c
> > @@ -356,6 +356,13 @@ fbdev_frame_buffer_open(struct fbdev_output *output, const char *fb_dev,
> >  		return -1;
> >  	}
> >  
> > +	/* Attempt to correct the framebuffer settings */
> > +	if (fbdev_set_screen_info(output, fd,
> > +	                          &output->fb_info) < 0) {
> > +		weston_log("Failed to set mode settings. "
> > +		           "Attempting to open output anyway.\n");
> > +	}
> > +
> >  	/* Grab the screen info. */
> >  	if (fbdev_query_screen_info(output, fd, screen_info) < 0) {
> >  		weston_log("Failed to get frame buffer info: %s\n",
> >   
> Hi
> 
> Nix this one, I tried it on a UDL (USB display link device) framebuffer, and it
> changes the resolution/vsync that my screen cannot handle, and I'll need to 
> figure out why it does that (as UDL (the framebuffer only one) starts off) with
> the screen all green...
> 
> ...It worked for QEMU, but not for real hardware
> 
> Sorry about this...
> ...I'll try to see what I can come up with, and why it does that....

Hi,

yeah, we definitely do not want to set_screen_info before first
query_screen_info. If there is something valid set already, we want to
keep it. If there is not, then how do you know what to set?

What screen info values do you think this patch is setting? All
zeroes? ;-)


Thanks,
pq
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