From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uli Luckas Subject: Re: Frame buffers and early i2c Date: Mon, 9 Jun 2008 23:59:35 +0200 Message-ID: <200806092359.36080.u.luckas@road.de> References: <200806091647.42757.u.luckas@road.de> <20080609205212.4b0f1ba6@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20080609205212.4b0f1ba6-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: i2c-bounces-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Errors-To: i2c-bounces-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org To: Jean Delvare Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, adaplas-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Linux I2C List-Id: linux-i2c@vger.kernel.org On Monday 09 June 2008, Jean Delvare wrote: > On Mon, 9 Jun 2008 16:47:42 +0200, Uli Luckas wrote: > > I am in the process of trying out a display connected to a colibri > > board's pxa frame buffer device. The display's power supply is switch > > through i2c. > > > > In order to use the frame buffer console I have i2c and pxafb compiled > > in. > > > > By default, the pxafb driver get's initialized before the i2c bus causing > > the display power up to fail. > > > > What do i2c people think about changing the link order here? > > Why don't you ask on the i2c mailing list? Cc added. > I wanted to get i2c developers plus frame buffer and other i2c client developers involved. Crossposting to more then 2 lists seemed wrong. > Personally I have no objection, but dependencies can be tricky so > you'll have to be careful. video is early in the link order at the > moment. > Yep. I might come back for help on that later. > > What do other frame buffer drivers handle the absence of i2c during early > > boot? > > Interestingly enough, they appear to do fine, despite the linking > order. Maybe because i2c_init is a subsys_initcall() while framebuffer > drivers are initialized with module_init()? Then I'm not sure why your > own driver has a problem there. > Well, this is only very partially true. Try: rgrep -l subsys_initcall drivers/i2c/ rgrep -l module_init drivers/i2c/ The last of which gives drivers/i2c/busses/i2c-pxa.c for example. I'll change the pxa i2c driver to subsys_initcall and try if that works when I get back to my desk tomorrow. regards, Uli _______________________________________________ i2c mailing list i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org http://lists.lm-sensors.org/mailman/listinfo/i2c