Re: [PATCH 05/32] OMAPDSS: fix dss_get_ctx_loss_count for DT

[Kevin Hilman <khilman@linaro.org>]

Tomi Valkeinen <tomi.valkeinen@ti.com> writes:

> When using DT, dss device does not have platform data. However,
> dss_get_ctx_loss_count() uses dss device's platform data to find the
> get_ctx_loss_count function pointer.
>
> To fix this, dss_get_ctx_loss_count() needs to be changed to get the
> platform data from the omapdss device, which is a "virtual" device and
> always has platform data.

Dumb question (since the DSS device model has always been beyond my
grasp): how/why does the virtual device still have platform_data on a DT
boot?

Also, this context_loss_count and DT boot is starting to get cumbersome,
and there's currently no (good) way of handling the context loss in a
generic way without pdata function pointers.

I'm starting to think we should move towards dropping this OMAP-specific
context loss counting, and just assume context is always lost.  If there
are performance problems, runtime PM autosuspend timeouts can be used to
avoid the transitions.

Or, on some devices, I suspect comparing a few registers against their
power-on reset values might be a quicker way of detecting lost context
and would avoid having to call into platform code all together.

Kevin

> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
>  drivers/video/omap2/dss/dss.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/omap2/dss/dss.c b/drivers/video/omap2/dss/dss.c
> index 94f66f9..bd01608 100644
> --- a/drivers/video/omap2/dss/dss.c
> +++ b/drivers/video/omap2/dss/dss.c
> @@ -157,7 +157,8 @@ static void dss_restore_context(void)
>  
>  int dss_get_ctx_loss_count(void)
>  {
> -	struct omap_dss_board_info *board_data = dss.pdev->dev.platform_data;
> +	struct platform_device *core_pdev = dss_get_core_pdev();
> +	struct omap_dss_board_info *board_data = core_pdev->dev.platform_data;
>  	int cnt;
>  
>  	if (!board_data->get_context_loss_count)