[Intel-gfx] [PATCH resend 12/15] drm/i915/dsi: Document always using v3 SHUTDOWN / MIPI_SEQ_DISPLAY_OFF order

[Bob Paauwe]

On Mon, 20 Feb 2017 15:08:42 +0100
Hans de Goede <hdegoede at redhat.com> wrote:

> According to the spec for v2 VBTs we should call MIPI_SEQ_DISPLAY_OFF
> before sending SHUTDOWN, where as for v3 VBTs we should send SHUTDOWN
> first.
> 
> Since the v2 order has known issues, we use the v3 order everywhere,
> add a comment documenting this.
> 
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
>  drivers/gpu/drm/i915/intel_dsi.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index a8d0948..1914311 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -732,6 +732,11 @@ static void intel_dsi_pre_disable(struct intel_encoder *encoder,
>  			I915_WRITE(MIPI_DEVICE_READY(port), 0);
>  	}
>  
> +	/*
> +	 * XXX: According to the spec we should send SHUTDOWN before
> +	 * MIPI_SEQ_DISPLAY_OFF only for v3+ VBTs, but testing in the field
> +	 * has shown that we should do this for v2 VBTs too?
drop the '?'
> +	 */
>  	if (is_vid_mode(intel_dsi)) {
>  		/* Send Shutdown command to the panel in LP mode */
>  		for_each_dsi_port(port, intel_dsi->ports)
> @@ -764,6 +769,8 @@ static void intel_dsi_post_disable(struct intel_encoder *encoder,
>  	/*
>  	 * if disable packets are sent before sending shutdown packet then in
>  	 * some next enable sequence send turn on packet error is observed
> +	 * XXX spec specifies SHUTDOWN before MIPI_SEQ_DISPLAY_OFF for
> +	 * v3 VBTs, but not for v2 VBTs?
>  	 */
>  	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_DISPLAY_OFF);
>  

Should XXX be replaced with something? 



-- 
--
Bob Paauwe                  
Bob.J.Paauwe at intel.com
IOTG / PED Software Organization
Intel Corp.  Folsom, CA
(916) 356-6193