Re: [PATCH 10/11] drm/i915: Add 180 degree primary plane rotation support

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Sat, Feb 01, 2014 at 12:40:46AM +0530, sagar.a.kamble@intel.com wrote:
> From: Sagar Kamble <sagar.a.kamble@intel.com>
> 
> Primary planes support 180 degree rotation. Expose the feature
> through rotation drm property.
> 
> Signed-off-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Sagar Kamble <sagar.a.kamble@intel.com>
> Tested-by: Sagar Kamble <sagar.a.kamble@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h      |  1 +
>  drivers/gpu/drm/i915/intel_display.c | 54 ++++++++++++++++++++++++++++++++++--
>  drivers/gpu/drm/i915/intel_drv.h     |  2 ++
>  3 files changed, 55 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 57906c5..d3000c4 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3553,6 +3553,7 @@
>  #define   DISPPLANE_NO_LINE_DOUBLE		0
>  #define   DISPPLANE_STEREO_POLARITY_FIRST	0
>  #define   DISPPLANE_STEREO_POLARITY_SECOND	(1<<18)
> +#define   DISPPLANE_ROTATE_180			(1<<15)
>  #define   DISPPLANE_TRICKLE_FEED_DISABLE	(1<<14) /* Ironlake */
>  #define   DISPPLANE_TILED			(1<<10)
>  #define _DSPAADDR		(dev_priv->info->display_mmio_offset + 0x70184)
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 4d4a0d9..483de59 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2037,6 +2037,7 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
>  	unsigned long linear_offset;
>  	u32 dspcntr;
>  	u32 reg;
> +	int pixel_size;
>  
>  	switch (plane) {
>  	case 0:
> @@ -2047,6 +2048,7 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
>  		return -EINVAL;
>  	}
>  
> +	pixel_size = drm_format_plane_cpp(fb->pixel_format, 0);
>  	intel_fb = to_intel_framebuffer(fb);
>  	obj = intel_fb->obj;
>  
> @@ -2054,6 +2056,8 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
>  	dspcntr = I915_READ(reg);
>  	/* Mask out pixel format bits in case we change it */
>  	dspcntr &= ~DISPPLANE_PIXFORMAT_MASK;
> +	dspcntr &= ~DISPPLANE_ROTATE_180;
> +
>  	switch (fb->pixel_format) {
>  	case DRM_FORMAT_C8:
>  		dspcntr |= DISPPLANE_8BPP;
> @@ -2095,8 +2099,6 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
>  	if (IS_G4X(dev))
>  		dspcntr |= DISPPLANE_TRICKLE_FEED_DISABLE;
>  
> -	I915_WRITE(reg, dspcntr);
> -
>  	linear_offset = y * fb->pitches[0] + x * (fb->bits_per_pixel / 8);
>  
>  	if (INTEL_INFO(dev)->gen >= 4) {
> @@ -2109,6 +2111,17 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
>  		intel_crtc->dspaddr_offset = linear_offset;
>  	}
>  
> +	if (intel_crtc->rotation == BIT(DRM_ROTATE_180)) {
> +		dspcntr |= DISPPLANE_ROTATE_180;
> +
> +		x += (fb->width - 1);
> +		y += (fb->height - 1);
> +		linear_offset += (fb->height - 1) * fb->pitches[0] +
> +                                   fb->width * pixel_size;
> +	}

This isn't quite right. We need something like:
x += pipe_src_w - 1;
y += pipe_src_h - 1;

That suggests your tests don't check if panning works correctly when
rotated.

I was also going to say we need to do this before stashing the result
into intel_crtc->dspaddr_offset on gen2/3, but it actually looks like
rotation is a gen4+ feature, so this place looks OK for this code.

You've also forgotten to add the rotation bits to
ironlake_update_plane(). That one will need additional HSW/BDW checks
I think.

> +
> +	I915_WRITE(reg, dspcntr);
> +
>  	DRM_DEBUG_KMS("Writing base %08lX %08lX %d %d %d\n",
>  		      i915_gem_obj_ggtt_offset(obj), linear_offset, x, y,
>  		      fb->pitches[0]);
> @@ -8748,6 +8761,31 @@ free_work:
>  	return ret;
>  }
>  
> +static int intel_crtc_set_property(struct drm_crtc *crtc,
> +				    struct drm_property *prop,
> +				    uint64_t val)
> +{
> +	struct drm_device *dev = crtc->dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> +	uint64_t old_val;
> +	int ret = -ENOENT;
> +
> +	if (prop == dev_priv->rotation_property) {
> +		/* exactly one rotation angle please */
> +		if (hweight32(val & 0xf) != 1)
> +			return -EINVAL;
> +
> +		old_val = intel_crtc->rotation;
> +		intel_crtc->rotation = val;
> +		ret = dev_priv->display.update_plane(crtc, crtc->fb, 0, 0);
> +		if (ret)
> +			intel_crtc->rotation = old_val;
> +	}
> +
> +	return ret;
> +}
> +
>  static struct drm_crtc_helper_funcs intel_helper_funcs = {
>  	.mode_set_base_atomic = intel_pipe_set_base_atomic,
>  	.load_lut = intel_crtc_load_lut,
> @@ -10160,6 +10198,7 @@ static const struct drm_crtc_funcs intel_crtc_funcs = {
>  	.set_config = intel_crtc_set_config,
>  	.destroy = intel_crtc_destroy,
>  	.page_flip = intel_crtc_page_flip,
> +	.set_property = intel_crtc_set_property
>  };
>  
>  static void intel_cpu_pll_init(struct drm_device *dev)
> @@ -10288,6 +10327,7 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
>  	 */
>  	intel_crtc->pipe = pipe;
>  	intel_crtc->plane = pipe;
> +	intel_crtc->rotation = BIT(DRM_ROTATE_0);
>  	if (HAS_FBC(dev) && INTEL_INFO(dev)->gen < 4) {
>  		DRM_DEBUG_KMS("swapping pipes & planes for FBC\n");
>  		intel_crtc->plane = !pipe;
> @@ -10298,6 +10338,16 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
>  	dev_priv->plane_to_crtc_mapping[intel_crtc->plane] = &intel_crtc->base;
>  	dev_priv->pipe_to_crtc_mapping[intel_crtc->pipe] = &intel_crtc->base;
>  
> +	if (!dev_priv->rotation_property)
> +		dev_priv->rotation_property =
> +			drm_mode_create_rotation_property(dev,
> +							BIT(DRM_ROTATE_0) |
> +							BIT(DRM_ROTATE_180));
> +	if (dev_priv->rotation_property)
> +		drm_object_attach_property(&intel_crtc->base.base,
> +					dev_priv->rotation_property,
> +					intel_crtc->rotation);

As I mentioned it looks like rotation is only supported starting from
gen4. So we need to check for that here before we add the props.

> +
>  	drm_crtc_helper_add(&intel_crtc->base, &intel_helper_funcs);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 7a79b8e..02dfdb6 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -331,6 +331,8 @@ struct intel_crtc {
>  	struct drm_crtc base;
>  	enum pipe pipe;
>  	enum plane plane;
> +	unsigned int rotation;
> +
>  	u8 lut_r[256], lut_g[256], lut_b[256];
>  	/*
>  	 * Whether the crtc and the connected output pipeline is active. Implies
> -- 
> 1.8.5
> 
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-- 
Ville Syrjälä
Intel OTC