Re: [PATCH] [#7001] framebuffer: old image of last app would retain for a while after starting new app

--===============0812645427006883287==
Content-Type: multipart/signed; boundary="nextPart3038206.pXqWmr0Egd";
	protocol="application/pgp-signature"; micalg=pgp-sha1
Content-Transfer-Encoding: 7bit

--nextPart3038206.pXqWmr0Egd
Content-Type: Text/Plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

On Thursday 15 March 2012 23:34:08 Zhang, Sonic wrote:
> From: Mike Frysinger [mailto:[email protected]]
>> 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.
>>=20
>> i'm not sure the behavior you describe is wrong.  in fact, i'm pretty su=
re
>> 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.
>=20
> Before the second application draws its own image, the image of last
> application has already been displayed on the LCD when the second
> application opens the FB device(PPI is enabled when it is opened). This is
> not a correct behavior.

sure it is.  if the app wants to clear the screen, it can do so.  generally=
=20
it's going to anyways by drawing an entire frame.  having the frame buffer=
=20
driver always clear the screen introduces wasted memory overhead as it does=
=20
the memset(), and user-visible jank as the device transitions from an initi=
al=20
splash screen to the main userspace app.

this is a policy decision that doesn't really belong in kernel space.  and =
if=20
it did, it should be agreed upon by all frame buffer users and not just=20
changing a few drivers.
=2Dmike

--nextPart3038206.pXqWmr0Egd
Content-Type: application/pgp-signature; name=signature.asc 
Content-Description: This is a digitally signed message part.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (GNU/Linux)
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=ciMM
-----END PGP SIGNATURE-----

--nextPart3038206.pXqWmr0Egd--


--===============0812645427006883287==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

------------------------------------------------------------------------------
This SF email is sponsosred by:
Try Windows Azure free for 90 days Click Here 
http://p.sf.net/sfu/sfd2d-msazure
--===============0812645427006883287==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
Linux-fbdev-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-fbdev-devel

--===============0812645427006883287==--