[Intel-gfx] [PATCH 01/16] drm/i915: Fix gen2 planes B and C max watermark value

[Thomas Richter]

On 15.08.2014 00:21, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> The max watermark value for gen2 planes B and C is 0x1f, instead of
> the 0x3f that plane A uses.
>
> Also check against the max even if the pipe is disabled since the
> FIFO size exceeds the plane B and C max watermark value.
>

Tested-by: Thomas Richter <richter at rus.uni-stuttgart.de>

> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>   drivers/gpu/drm/i915/intel_pm.c | 24 ++++++++++++++++++++----
>   1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 12f4e14..f696b7f 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -985,13 +985,20 @@ static const struct intel_watermark_params i915_wm_info = {
>   	.guard_size = 2,
>   	.cacheline_size = I915_FIFO_LINE_SIZE,
>   };
> -static const struct intel_watermark_params i830_wm_info = {
> +static const struct intel_watermark_params i830_a_wm_info = {
>   	.fifo_size = I855GM_FIFO_SIZE,
>   	.max_wm = I915_MAX_WM,
>   	.default_wm = 1,
>   	.guard_size = 2,
>   	.cacheline_size = I830_FIFO_LINE_SIZE,
>   };
> +static const struct intel_watermark_params i830_bc_wm_info = {
> +	.fifo_size = I855GM_FIFO_SIZE,
> +	.max_wm = I915_MAX_WM/2,
> +	.default_wm = 1,
> +	.guard_size = 2,
> +	.cacheline_size = I830_FIFO_LINE_SIZE,
> +};
>   static const struct intel_watermark_params i845_wm_info = {
>   	.fifo_size = I830_FIFO_SIZE,
>   	.max_wm = I915_MAX_WM,
> @@ -1673,7 +1680,7 @@ static void i9xx_update_wm(struct drm_crtc *unused_crtc)
>   	else if (!IS_GEN2(dev))
>   		wm_info = &i915_wm_info;
>   	else
> -		wm_info = &i830_wm_info;
> +		wm_info = &i830_a_wm_info;
>
>   	fifo_size = dev_priv->display.get_fifo_size(dev, 0);
>   	crtc = intel_get_crtc_for_plane(dev, 0);
> @@ -1688,8 +1695,14 @@ static void i9xx_update_wm(struct drm_crtc *unused_crtc)
>   					       wm_info, fifo_size, cpp,
>   					       latency_ns);
>   		enabled = crtc;
> -	} else
> +	} else {
>   		planea_wm = fifo_size - wm_info->guard_size;
> +		if (planea_wm > (long)wm_info->max_wm)
> +			planea_wm = wm_info->max_wm;
> +	}
> +
> +	if (IS_GEN2(dev))
> +		wm_info = &i830_bc_wm_info;
>
>   	fifo_size = dev_priv->display.get_fifo_size(dev, 1);
>   	crtc = intel_get_crtc_for_plane(dev, 1);
> @@ -1707,8 +1720,11 @@ static void i9xx_update_wm(struct drm_crtc *unused_crtc)
>   			enabled = crtc;
>   		else
>   			enabled = NULL;
> -	} else
> +	} else {
>   		planeb_wm = fifo_size - wm_info->guard_size;
> +		if (planeb_wm > (long)wm_info->max_wm)
> +			planeb_wm = wm_info->max_wm;
> +	}
>
>   	DRM_DEBUG_KMS("FIFO watermarks - A: %d, B: %d\n", planea_wm, planeb_wm);
>
>