From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out01.alice.it (smtp-out01.alice.it [85.33.2.12]) by ozlabs.org (Postfix) with ESMTP id 37BD8B7BBC for ; Fri, 23 Oct 2009 21:00:13 +1100 (EST) Message-ID: <4AE17E97.40907@tin.it> Date: Fri, 23 Oct 2009 11:59:51 +0200 From: LD MIME-Version: 1.0 To: Chen Hongjun-R66092 Subject: Re: MPC5121e DIU driver - kernel crash writing alpha component References: <4AE1585E.60002@tin.it> <3A45394FD742FA419B760BB8D398F9ED8F6CF3@zch01exm26.fsl.freescale.net> In-Reply-To: <3A45394FD742FA419B760BB8D398F9ED8F6CF3@zch01exm26.fsl.freescale.net> Content-Type: text/plain; charset=ISO-8859-1 Cc: Linux ppc mailing list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Chen, many thanks for your very fast answer. If I understand well, the situation is as follows: 32 bits mode, plane1 - if I write any alpha component != 0 I have a system hang ; writing alpha components in any other plane is ok. - ----- - From my first tries I had lockups also in 16 bits 5-6-5 modes, but in this moment I cannot precisely track down things. Is there something I cannot do in plane1 in 16 bits modes ? - ----- With the previous processor stepping I was not experiencing this problem ; is it something specific from 0M36P ? - ----- - From this, if I cannot write something in plane1 I would think about a kernel display driver patch: a user program ->can not<- lock the system by writing something wrong. So... two paths: - - do not "publish" plane1 as /dev/fb0, but plane2 will be /dev/fb0 or - - see suggestion about double buffering and filtering alpha components Thanks, best regards Lucio Dona' Chen Hongjun-R66092 wrote: >> Hi, > >> Pls refer to my comment embedded. > > > The board is booting ok (NFS), but my user space app keeps > crashing the kernel. > > If, from user space, I write some alpha component != 0 in > this plane then I have a complete system crash. > The reference pdf says "There is no alpha component defined > for plane1 because there are no planes behind it." > > >> Sure, panel0 doesn't support alpha function, so you can't operate it. > > >> You can replace panel0 with panel1, which can support alpha function. > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iD8DBQFK4X6XvxHCsvXy9okRApsxAJ40VJ+2/+sP4XW1qoviZlQm6m+0HQCgjkmB p2zNmK+Eyf++r9w0fEQxZxs= =HWm0 -----END PGP SIGNATURE-----