[Intel-gfx] [PATCH 2/3] drm/i915: wait for all DSI FIFOs to be empty

[Imre Deak]

On Sat, 2014-07-12 at 17:17 +0530, Shobhit Kumar wrote:
> Ensure that the DSI packets for a particular sequence are completely
> sent before going ahead in the enabling or disabling of the panel
> 
> Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>

Reviewed-by: Imre Deak <imre.deak at intel.com>

> ---
>  drivers/gpu/drm/i915/intel_dsi.c     |  8 ++++++++
>  drivers/gpu/drm/i915/intel_dsi_cmd.c | 16 ++++++++++++++++
>  drivers/gpu/drm/i915/intel_dsi_cmd.h |  1 +
>  3 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index 61da0e5..98c78ab 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -152,6 +152,8 @@ static void intel_dsi_enable(struct intel_encoder *encoder)
>  		if (intel_dsi->dev.dev_ops->enable)
>  			intel_dsi->dev.dev_ops->enable(&intel_dsi->dev);
>  
> +		wait_for_dsi_fifo_empty(intel_dsi);
> +
>  		/* assert ip_tg_enable signal */
>  		temp = I915_READ(MIPI_PORT_CTRL(pipe)) & ~LANE_CONFIGURATION_MASK;
>  		temp = temp | intel_dsi->port_bits;
> @@ -192,6 +194,8 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
>  	if (intel_dsi->dev.dev_ops->send_otp_cmds)
>  		intel_dsi->dev.dev_ops->send_otp_cmds(&intel_dsi->dev);
>  
> +	wait_for_dsi_fifo_empty(intel_dsi);
> +
>  	/* Enable port in pre-enable phase itself because as per hw team
>  	 * recommendation, port should be enabled befor plane & pipe */
>  	intel_dsi_enable(encoder);
> @@ -232,6 +236,8 @@ static void intel_dsi_disable(struct intel_encoder *encoder)
>  	DRM_DEBUG_KMS("\n");
>  
>  	if (is_vid_mode(intel_dsi)) {
> +		wait_for_dsi_fifo_empty(intel_dsi);
> +
>  		/* de-assert ip_tg_enable signal */
>  		temp = I915_READ(MIPI_PORT_CTRL(pipe));
>  		I915_WRITE(MIPI_PORT_CTRL(pipe), temp & ~DPI_ENABLE);
> @@ -261,6 +267,8 @@ static void intel_dsi_disable(struct intel_encoder *encoder)
>  	 * some next enable sequence send turn on packet error is observed */
>  	if (intel_dsi->dev.dev_ops->disable)
>  		intel_dsi->dev.dev_ops->disable(&intel_dsi->dev);
> +
> +	wait_for_dsi_fifo_empty(intel_dsi);
>  }
>  
>  static void intel_dsi_clear_device_ready(struct intel_encoder *encoder)
> diff --git a/drivers/gpu/drm/i915/intel_dsi_cmd.c b/drivers/gpu/drm/i915/intel_dsi_cmd.c
> index 933c863..7f1430a 100644
> --- a/drivers/gpu/drm/i915/intel_dsi_cmd.c
> +++ b/drivers/gpu/drm/i915/intel_dsi_cmd.c
> @@ -419,3 +419,19 @@ int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs)
>  
>  	return 0;
>  }
> +
> +void wait_for_dsi_fifo_empty(struct intel_dsi *intel_dsi)
> +{
> +	struct drm_encoder *encoder = &intel_dsi->base.base;
> +	struct drm_device *dev = encoder->dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
> +	enum pipe pipe = intel_crtc->pipe;
> +	u32 mask;
> +
> +	mask = LP_CTRL_FIFO_EMPTY | HS_CTRL_FIFO_EMPTY |
> +					LP_DATA_FIFO_EMPTY | HS_DATA_FIFO_EMPTY;
> +
> +	if (wait_for((I915_READ(MIPI_GEN_FIFO_STAT(pipe)) & mask) == mask, 100))
> +		DRM_ERROR("DPI FIFOs are not empty\n");
> +}
> diff --git a/drivers/gpu/drm/i915/intel_dsi_cmd.h b/drivers/gpu/drm/i915/intel_dsi_cmd.h
> index 9a18cbf..46aa1ac 100644
> --- a/drivers/gpu/drm/i915/intel_dsi_cmd.h
> +++ b/drivers/gpu/drm/i915/intel_dsi_cmd.h
> @@ -51,6 +51,7 @@ int dsi_vc_generic_read(struct intel_dsi *intel_dsi, int channel,
>  			u8 *reqdata, int reqlen, u8 *buf, int buflen);
>  
>  int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs);
> +void wait_for_dsi_fifo_empty(struct intel_dsi *intel_dsi);
>  
>  /* XXX: questionable write helpers */
>  static inline int dsi_vc_dcs_write_0(struct intel_dsi *intel_dsi,

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