Re: [PATCH] drm/msm/mdp5: Always generate active-high sync signals for DSI

[Archit Taneja]

On 05/22/2015 07:46 PM, Hai Li wrote:
> DSI video mode engine can only take active-high sync signals. This
> change prevents MDP5 sending active-low sync signals to DSI in any
> case.
>
> Signed-off-by: Hai Li <hali@xxxxxxxxxxxxxx>

Tested-by: Archit Taneja <architt@xxxxxxxxxxxxxx>

> ---
>   drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
> index 53bb1f7..2e98ce0 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
> @@ -144,10 +144,14 @@ static void mdp5_encoder_mode_set(struct drm_encoder *encoder,
>   			mode->type, mode->flags);
>
>   	ctrl_pol = 0;
> -	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
> -		ctrl_pol |= MDP5_INTF_POLARITY_CTL_HSYNC_LOW;
> -	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> -		ctrl_pol |= MDP5_INTF_POLARITY_CTL_VSYNC_LOW;
> +
> +	/* DSI controller cannot handle active-low sync signals. */
> +	if (mdp5_encoder->intf.type != INTF_DSI) {
> +		if (mode->flags & DRM_MODE_FLAG_NHSYNC)
> +			ctrl_pol |= MDP5_INTF_POLARITY_CTL_HSYNC_LOW;
> +		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> +			ctrl_pol |= MDP5_INTF_POLARITY_CTL_VSYNC_LOW;
> +	}
>   	/* probably need to get DATA_EN polarity from panel.. */
>
>   	dtv_hsync_skew = 0;  /* get this from panel? */

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