diff mbox

drm/vc4: Add support for plane alpha

Message ID 20180420230503.9629-1-stschake@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Stefan Schake April 20, 2018, 11:05 p.m. UTC
The HVS supports mixing fixed alpha with per-pixel alpha or
setting a fixed plane alpha in case there is no per-pixel information.
This allows us to support the generic DRM plane alpha property.

Signed-off-by: Stefan Schake <stschake@gmail.com>
---
 drivers/gpu/drm/vc4/vc4_plane.c | 14 +++++++++++++-
 drivers/gpu/drm/vc4/vc4_regs.h  |  1 +
 2 files changed, 14 insertions(+), 1 deletion(-)

Comments

Eric Anholt April 20, 2018, 11:45 p.m. UTC | #1
Stefan Schake <stschake@gmail.com> writes:

> The HVS supports mixing fixed alpha with per-pixel alpha or
> setting a fixed plane alpha in case there is no per-pixel information.
> This allows us to support the generic DRM plane alpha property.

Don't we need to set needs_bg_fill based on alpha != OPAQUE, as well?

Other than that, looks good to me.
Stefan Schake April 21, 2018, 12:07 a.m. UTC | #2
On Sat, Apr 21, 2018 at 1:45 AM, Eric Anholt <eric@anholt.net> wrote:
> Stefan Schake <stschake@gmail.com> writes:
>
>> The HVS supports mixing fixed alpha with per-pixel alpha or
>> setting a fixed plane alpha in case there is no per-pixel information.
>> This allows us to support the generic DRM plane alpha property.
>
> Don't we need to set needs_bg_fill based on alpha != OPAQUE, as well?
>
> Other than that, looks good to me.

I did forget about the whole background situation, and a quick test
shows you are right: anything less than opaque has the funky
repeating pattern artifact.

Thanks, I'll send a new version.
kernel test robot April 22, 2018, 6:56 p.m. UTC | #3
Hi Stefan,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on v4.17-rc1]
[also build test ERROR on next-20180420]
[cannot apply to anholt/for-next]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Stefan-Schake/drm-vc4-Add-support-for-plane-alpha/20180423-002110
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=sh 

All errors (new ones prefixed by >>):

   drivers/gpu/drm/vc4/vc4_plane.c: In function 'vc4_plane_reset':
>> drivers/gpu/drm/vc4/vc4_plane.c:204:14: error: 'struct drm_plane_state' has no member named 'alpha'
     plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
                 ^~
>> drivers/gpu/drm/vc4/vc4_plane.c:204:24: error: 'DRM_BLEND_ALPHA_OPAQUE' undeclared (first use in this function)
     plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
                           ^~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/vc4/vc4_plane.c:204:24: note: each undeclared identifier is reported only once for each function it appears in
   In file included from drivers/gpu/drm/vc4/vc4_plane.c:28:0:
   drivers/gpu/drm/vc4/vc4_plane.c: In function 'vc4_plane_mode_set':
   drivers/gpu/drm/vc4/vc4_plane.c:557:23: error: 'struct drm_plane_state' has no member named 'alpha'
       VC4_SET_FIELD(state->alpha >> 8, SCALER_POS0_FIXED_ALPHA) |
                          ^
   drivers/gpu/drm/vc4/vc4_regs.h:18:24: note: in definition of macro 'VC4_SET_FIELD'
      uint32_t fieldval = (value) << field##_SHIFT;  \
                           ^~~~~
   drivers/gpu/drm/vc4/vc4_plane.c:574:25: error: 'struct drm_plane_state' has no member named 'alpha'
     mix_plane_alpha = state->alpha != DRM_BLEND_ALPHA_OPAQUE &&
                            ^~
   drivers/gpu/drm/vc4/vc4_plane.c:574:36: error: 'DRM_BLEND_ALPHA_OPAQUE' undeclared (first use in this function)
     mix_plane_alpha = state->alpha != DRM_BLEND_ALPHA_OPAQUE &&
                                       ^~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/vc4/vc4_plane.c: In function 'vc4_plane_init':
>> drivers/gpu/drm/vc4/vc4_plane.c:952:2: error: implicit declaration of function 'drm_plane_create_alpha_property'; did you mean 'drm_plane_create_zpos_property'? [-Werror=implicit-function-declaration]
     drm_plane_create_alpha_property(plane);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     drm_plane_create_zpos_property
   cc1: some warnings being treated as errors

vim +204 drivers/gpu/drm/vc4/vc4_plane.c

   191	
   192	/* Called during init to allocate the plane's atomic state. */
   193	static void vc4_plane_reset(struct drm_plane *plane)
   194	{
   195		struct vc4_plane_state *vc4_state;
   196	
   197		WARN_ON(plane->state);
   198	
   199		vc4_state = kzalloc(sizeof(*vc4_state), GFP_KERNEL);
   200		if (!vc4_state)
   201			return;
   202	
   203		plane->state = &vc4_state->base;
 > 204		plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
   205		vc4_state->base.plane = plane;
   206	}
   207	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox

Patch

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index c3a37a99e601..b06e0ec013c5 100644
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -201,6 +201,7 @@  static void vc4_plane_reset(struct drm_plane *plane)
 		return;
 
 	plane->state = &vc4_state->base;
+	plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
 	vc4_state->base.plane = plane;
 }
 
@@ -467,6 +468,7 @@  static int vc4_plane_mode_set(struct drm_plane *plane,
 	u32 ctl0_offset = vc4_state->dlist_count;
 	const struct hvs_format *format = vc4_get_hvs_format(fb->format->format);
 	int num_planes = drm_format_num_planes(format->drm);
+	bool mix_plane_alpha;
 	bool covers_screen;
 	u32 scl0, scl1, pitch0;
 	u32 lbm_size, tiling;
@@ -552,7 +554,7 @@  static int vc4_plane_mode_set(struct drm_plane *plane,
 	/* Position Word 0: Image Positions and Alpha Value */
 	vc4_state->pos0_offset = vc4_state->dlist_count;
 	vc4_dlist_write(vc4_state,
-			VC4_SET_FIELD(0xff, SCALER_POS0_FIXED_ALPHA) |
+			VC4_SET_FIELD(state->alpha >> 8, SCALER_POS0_FIXED_ALPHA) |
 			VC4_SET_FIELD(vc4_state->crtc_x, SCALER_POS0_START_X) |
 			VC4_SET_FIELD(vc4_state->crtc_y, SCALER_POS0_START_Y));
 
@@ -565,6 +567,13 @@  static int vc4_plane_mode_set(struct drm_plane *plane,
 					      SCALER_POS1_SCL_HEIGHT));
 	}
 
+	/* Don't waste cycles mixing with plane alpha if the set alpha
+	 * is opaque or there is no per-pixel alpha information.
+	 * In any case we use the alpha property value as the fixed alpha.
+	 */
+	mix_plane_alpha = state->alpha != DRM_BLEND_ALPHA_OPAQUE &&
+			  fb->format->has_alpha;
+
 	/* Position Word 2: Source Image Size, Alpha */
 	vc4_state->pos2_offset = vc4_state->dlist_count;
 	vc4_dlist_write(vc4_state,
@@ -572,6 +581,7 @@  static int vc4_plane_mode_set(struct drm_plane *plane,
 				      SCALER_POS2_ALPHA_MODE_PIPELINE :
 				      SCALER_POS2_ALPHA_MODE_FIXED,
 				      SCALER_POS2_ALPHA_MODE) |
+			(mix_plane_alpha ? SCALER_POS2_ALPHA_MIX : 0) |
 			(fb->format->has_alpha ? SCALER_POS2_ALPHA_PREMULT : 0) |
 			VC4_SET_FIELD(vc4_state->src_w[0], SCALER_POS2_WIDTH) |
 			VC4_SET_FIELD(vc4_state->src_h[0], SCALER_POS2_HEIGHT));
@@ -916,5 +926,7 @@  struct drm_plane *vc4_plane_init(struct drm_device *dev,
 
 	drm_plane_helper_add(plane, &vc4_plane_helper_funcs);
 
+	drm_plane_create_alpha_property(plane);
+
 	return plane;
 }
diff --git a/drivers/gpu/drm/vc4/vc4_regs.h b/drivers/gpu/drm/vc4/vc4_regs.h
index 4af3e29d076a..d1fb6fec46eb 100644
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -945,6 +945,7 @@  enum hvs_pixel_format {
 #define SCALER_POS2_ALPHA_MODE_FIXED_NONZERO	2
 #define SCALER_POS2_ALPHA_MODE_FIXED_OVER_0x07	3
 #define SCALER_POS2_ALPHA_PREMULT		BIT(29)
+#define SCALER_POS2_ALPHA_MIX			BIT(28)
 
 #define SCALER_POS2_HEIGHT_MASK			VC4_MASK(27, 16)
 #define SCALER_POS2_HEIGHT_SHIFT		16