Re: [Linux-fbdev-devel] Behaviour change of /dev/fb0?

From: Antonino A. Daplas
Date: Fri Apr 14 2006 - 19:38:58 EST


Richard Purdie wrote:
> Ignoring whether this is a good idea or not, under 2.6.15 you could run
>
> dd if=/dev/zero of=/dev/fb0
>
> which would clear the framebuffer. It would end up saying "dd: /dev/fb0:
> No space left on device".
>
> Under 2.6.16 (and a recent git kernel), the same command clears the
> screen but then hangs. Was the change in behaviour intentional?
>
> I've noticed this on a couple of ARM based Zaurus handhelds under both
> w100fb and pxafb.
>

There is a change in behavior of fb_read and fb_write committed Jan 2006.
They return the number of bytes read or written if the requested size
is bigger than the remaining space. Previously, they returned -ENOSPC.

But I haven't experienced hangs...

Tony
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