# Re: \[Linux-fbdev-devel\] \[uclinux-dist-devel\] \[PATCH\] \[\#7001\] framebuffer: old image of last app woul

- List: linux-fbdev
- 3 messages, 2 authors
- Page: https://ratatoskr.run/linux-fbdev/2012/03/13462779/t

## Re: \[Linux-fbdev-devel\] \[uclinux-dist-devel\] \[PATCH\] \[\#7001\] framebuffer: old image of last app woul

- From: Mike Frysinger \<hidden\>
- Date: 2012-03-15 19:08:03 
- Message: https://ratatoskr.run/linux-fbdev/2012/03/13462779.md

```text
On Thursday 15 March 2012 05:23:50 Wu, Aaron wrote:
> Old image of last application would retain for a while when starting a new
> application, this patch clear the frambuffer before displaying every time
> the fb is opened.

i'm not sure the behavior you describe is wrong.  in fact, i'm pretty sure it 
sounds correct.  if an app writes an image to the framebuffer and then quits, 
that image should stay there indefinitely until something else opens the 
framebuffer and draws their own image.
-mike
```

## Re: \[Linux-fbdev-devel\] \[uclinux-dist-devel\] \[PATCH\] \[\#7001\] framebuffer: old image of last app woul

- From: Geert Uytterhoeven \<geert@linux-m68k.org\>
- Date: 2012-03-15 19:22:34 
- Message: https://ratatoskr.run/linux-fbdev/2012/03/13462780.md

```text
[ Corrected obsolete linux-fbdev-devel address ]

On Thu, Mar 15, 2012 at 20:08, Mike Frysinger [ref] wrote:
> On Thursday 15 March 2012 05:23:50 Wu, Aaron wrote:
>> Old image of last application would retain for a while when starting a new
>> application, this patch clear the frambuffer before displaying every time
>> the fb is opened.
>
> i'm not sure the behavior you describe is wrong.  in fact, i'm pretty sure it
> sounds correct.  if an app writes an image to the framebuffer and then quits,
> that image should stay there indefinitely until something else opens the
> framebuffer and draws their own image.

Indeed. Else can you no longer make a screenshot using "cat /dev/fb0 > file".

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
```

## Re: \[Linux-fbdev-devel\] \[uclinux-dist-devel\] \[PATCH\] \[\#7001\] framebuffer: old image of last app woul

- From: Mike Frysinger \<hidden\>
- Date: 2012-03-15 19:29:20 
- Message: https://ratatoskr.run/linux-fbdev/2012/03/13462781.md

```text
On Thursday 15 March 2012 15:22:34 Geert Uytterhoeven wrote:
> On Thu, Mar 15, 2012 at 20:08, Mike Frysinger wrote:
> > On Thursday 15 March 2012 05:23:50 Wu, Aaron wrote:
> >> Old image of last application would retain for a while when starting a
> >> new application, this patch clear the frambuffer before displaying
> >> every time the fb is opened.
> > 
> > i'm not sure the behavior you describe is wrong.  in fact, i'm pretty
> > sure it sounds correct.  if an app writes an image to the framebuffer
> > and then quits, that image should stay there indefinitely until
> > something else opens the framebuffer and draws their own image.
> 
> Indeed. Else can you no longer make a screenshot using "cat /dev/fb0 >
> file".

ironically, that's one method we've documented for Blackfin platforms :)
http://docs.blackfin.uclinux.org/doku.php?id=uclinux-dist:framebuffer
-mike
```