On Thu, 2012-08-30 at 17:10 +0530, Archit Taneja wrote:
> Add output structs to output driver's private data. Register output instances by
> having an init function in the probes of the platform device drivers for
> different outputs. The *_init_output for each output registers the output and
> fill up the output's plaform device, type and id fields.
> 
> In the probe of each interface driver, the output entities are initialized
> before the *_probe_pdata() functions intentionally. This is done to ensure that
> the output entity is prepared before the panels connected to the output are
> registered. We need the output entities to be ready because OMAPDSS will try
> to make connections between overlays, managers, outputs and devices during the
> panel's probe.
> 
> Signed-off-by: Archit Taneja <archit@ti.com>
> ---
>  drivers/video/omap2/dss/dpi.c  |   15 +++++++++++++++
>  drivers/video/omap2/dss/dsi.c  |   18 ++++++++++++++++++
>  drivers/video/omap2/dss/hdmi.c |   15 +++++++++++++++
>  drivers/video/omap2/dss/rfbi.c |   17 +++++++++++++++++
>  drivers/video/omap2/dss/sdi.c  |   15 +++++++++++++++
>  drivers/video/omap2/dss/venc.c |   15 +++++++++++++++
>  6 files changed, 95 insertions(+)
> 
> diff --git a/drivers/video/omap2/dss/dpi.c b/drivers/video/omap2/dss/dpi.c
> index 25fb895..9a7aee5 100644
> --- a/drivers/video/omap2/dss/dpi.c
> +++ b/drivers/video/omap2/dss/dpi.c
> @@ -45,6 +45,8 @@ static struct {
>  	struct omap_video_timings timings;
>  	struct dss_lcd_mgr_config mgr_config;
>  	int data_lines;
> +
> +	struct omap_dss_output output;
>  } dpi;
>  
>  static struct platform_device *dpi_get_dsidev(enum omap_dss_clk_source clk)
> @@ -410,10 +412,23 @@ static void __init dpi_probe_pdata(struct platform_device *pdev)
>  	}
>  }
>  
> +static void __init dpi_init_output(struct platform_device *pdev)
> +{
> +	struct omap_dss_output *out = &dpi.output;
> +
> +	dss_register_output(out);
> +
> +	out->pdev = pdev;
> +	out->id = OMAP_DSS_OUTPUT_DPI;
> +	out->type = OMAP_DISPLAY_TYPE_DPI;
> +}

I think you should first initialize the output, and then register it.
Not the other way around.

I believe you need to implement unregister also. Normally unregister
won't be done, but the probe of an output driver can fail after the
output has been registered, and thus the output needs to be unregistered
at cleanup.

And it doesn't harm to unregister at the driver's remove.

 Tomi