[PATCH] drm/vc4: Fix with pm_runtime synchronization on DSI

[Eric Anholt]

Hoegeun Kwon <hoegeun.kwon at samsung.com> writes:

> There is a problem when often dpms goes from off to on. pm idle is not
> in sync and the problem occurs. Modify pm_runtime_put from
> asynchronous to synchronous.

Why would we need the power domain to go to off before we try to come
back?  Any idea?  Also, please specify what "the problem" is.

>
> Signed-off-by: Hoegeun Kwon <hoegeun.kwon at samsung.com>
> ---
>  drivers/gpu/drm/vc4/vc4_dsi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index 11702e1d9011..b0264c7b8bed 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -822,7 +822,7 @@ static void vc4_dsi_encoder_disable(struct drm_encoder *encoder)
>  	clk_disable_unprepare(dsi->escape_clock);
>  	clk_disable_unprepare(dsi->pixel_clock);
>  
> -	pm_runtime_put(dev);
> +	pm_runtime_put_sync(dev);
>  }
>  
>  /* Extends the mode's blank intervals to handle BCM2835's integer-only
> -- 
> 2.17.1
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