diff mbox series

[04/20] drm/fourcc: Pass the format_info pointer to drm_format_plane_width/height

Message ID 194fd02a37172de6f2a799fee5c98ced5e7e9d76.1555487650.git-series.maxime.ripard@bootlin.com (mailing list archive)
State New, archived
Headers show
Series drm: Split out the formats API and move it to a common place | expand

Commit Message

Maxime Ripard April 17, 2019, 7:54 a.m. UTC 
So far, the drm_format_plane_height/width functions were operating on the
format's fourcc and was doing a lookup to retrieve the drm_format_info
structure and return the cpp.

However, this is inefficient since in most cases, we will have the
drm_format_info pointer already available so we shouldn't have to perform a
new lookup. Some drm_fourcc functions also already operate on the
drm_format_info pointer for that reason, so the API is quite inconsistent
there.

Let's follow the latter pattern and remove the extra lookup while being a
bit more consistent.

In order to be extra consistent, also rename that function to
drm_format_info_plane_cpp and to a static function in the header to match
the current policy. The parameters order have also be changed to match the
other functions prototype.

Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 drivers/gpu/drm/drm_fourcc.c          | 48 +----------------------------
 drivers/gpu/drm/meson/meson_overlay.c | 12 +++----
 include/drm/drm_fourcc.h              | 46 +++++++++++++++++++++++++--
 3 files changed, 50 insertions(+), 56 deletions(-)

Comments

Maxime Ripard April 17, 2019, 11:01 a.m. UTC | #1 
On Wed, Apr 17, 2019 at 12:47:48PM +0200, Maarten Lankhorst wrote:
> > +/**
> > + * drm_format_info_plane_width - width of the plane given the first plane
> > + * @format: pixel format info
> > + * @width: width of the first plane
> > + * @plane: plane index
> > + *
> > + * Returns:
> > + * The width of @plane, given that the width of the first plane is @width.
> > + */
> > +static inline
> > +int drm_format_info_plane_width(const struct drm_format_info *info, int width,
> > +				int plane)
> > +{
> > +	if (!info || plane >= info->num_planes)
> > +		return 0;
> > +
> > +	if (plane == 0)
> > +		return width;
> > +
> > +	return width / info->hsub;
> > +}
> > +
> > +/**
> > + * drm_format_info_plane_height - height of the plane given the first plane
> > + * @format: pixel format info
> > + * @height: height of the first plane
> > + * @plane: plane index
> > + *
> > + * Returns:
> > + * The height of @plane, given that the height of the first plane is @height.
> > + */
> > +static inline
> > +int drm_format_info_plane_height(const struct drm_format_info *info, int height,
> > +				 int plane)
> > +{
> > +	if (!info || plane >= info->num_planes)
> > +		return 0;
> > +
> > +	if (plane == 0)
> > +		return height;
> > +
> > +	return height / info->vsub;
> > +}
>
> Why the null checks? None of the other inlines for drm_format_info
> perform them.

Unless I'm mistaken, the subsampling only applies to the planes with
the chrominance, which are always >= 1. Therefore the plane 0 is
always the luminance, to which the subsampling doesn't apply.

Or are you talking about something else?

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Maarten Lankhorst April 17, 2019, 11:10 a.m. UTC | #2 
Op 17-04-2019 om 13:01 schreef Maxime Ripard:
> On Wed, Apr 17, 2019 at 12:47:48PM +0200, Maarten Lankhorst wrote:
>>> +/**
>>> + * drm_format_info_plane_width - width of the plane given the first plane
>>> + * @format: pixel format info
>>> + * @width: width of the first plane
>>> + * @plane: plane index
>>> + *
>>> + * Returns:
>>> + * The width of @plane, given that the width of the first plane is @width.
>>> + */
>>> +static inline
>>> +int drm_format_info_plane_width(const struct drm_format_info *info, int width,
>>> +				int plane)
>>> +{
>>> +	if (!info || plane >= info->num_planes)
>>> +		return 0;
>>> +
>>> +	if (plane == 0)
>>> +		return width;
>>> +
>>> +	return width / info->hsub;
>>> +}
>>> +
>>> +/**
>>> + * drm_format_info_plane_height - height of the plane given the first plane
>>> + * @format: pixel format info
>>> + * @height: height of the first plane
>>> + * @plane: plane index
>>> + *
>>> + * Returns:
>>> + * The height of @plane, given that the height of the first plane is @height.
>>> + */
>>> +static inline
>>> +int drm_format_info_plane_height(const struct drm_format_info *info, int height,
>>> +				 int plane)
>>> +{
>>> +	if (!info || plane >= info->num_planes)
>>> +		return 0;
>>> +
>>> +	if (plane == 0)
>>> +		return height;
>>> +
>>> +	return height / info->vsub;
>>> +}
>> Why the null checks? None of the other inlines for drm_format_info
>> perform them.
> Unless I'm mistaken, the subsampling only applies to the planes with
> the chrominance, which are always >= 1. Therefore the plane 0 is
> always the luminance, to which the subsampling doesn't apply.
>
> Or are you talking about something else?


The info == NULL check. :)
Maxime Ripard April 17, 2019, 1:12 p.m. UTC | #3 
On Wed, Apr 17, 2019 at 01:10:33PM +0200, Maarten Lankhorst wrote:
> Op 17-04-2019 om 13:01 schreef Maxime Ripard:
> > On Wed, Apr 17, 2019 at 12:47:48PM +0200, Maarten Lankhorst wrote:
> >>> +/**
> >>> + * drm_format_info_plane_width - width of the plane given the first plane
> >>> + * @format: pixel format info
> >>> + * @width: width of the first plane
> >>> + * @plane: plane index
> >>> + *
> >>> + * Returns:
> >>> + * The width of @plane, given that the width of the first plane is @width.
> >>> + */
> >>> +static inline
> >>> +int drm_format_info_plane_width(const struct drm_format_info *info, int width,
> >>> +				int plane)
> >>> +{
> >>> +	if (!info || plane >= info->num_planes)
> >>> +		return 0;
> >>> +
> >>> +	if (plane == 0)
> >>> +		return width;
> >>> +
> >>> +	return width / info->hsub;
> >>> +}
> >>> +
> >>> +/**
> >>> + * drm_format_info_plane_height - height of the plane given the first plane
> >>> + * @format: pixel format info
> >>> + * @height: height of the first plane
> >>> + * @plane: plane index
> >>> + *
> >>> + * Returns:
> >>> + * The height of @plane, given that the height of the first plane is @height.
> >>> + */
> >>> +static inline
> >>> +int drm_format_info_plane_height(const struct drm_format_info *info, int height,
> >>> +				 int plane)
> >>> +{
> >>> +	if (!info || plane >= info->num_planes)
> >>> +		return 0;
> >>> +
> >>> +	if (plane == 0)
> >>> +		return height;
> >>> +
> >>> +	return height / info->vsub;
> >>> +}
> >> Why the null checks? None of the other inlines for drm_format_info
> >> perform them.
> > Unless I'm mistaken, the subsampling only applies to the planes with
> > the chrominance, which are always >= 1. Therefore the plane 0 is
> > always the luminance, to which the subsampling doesn't apply.
> >
> > Or are you talking about something else?
>
>
> The info == NULL check. :)

Aaah, sorry :)

That's true, and that's actually the first four patches that change
that behaviour a bit. Previously, drm_format_plane_cpp, _width, and
_height will do the lookup themselves using drm_format_info, and test
whether the pointer returned is null or not.

Patches 3 and 4 removed that lookup but kept the null pointer check.

We could remove it, but there's two downsides for that:

  * since the lookup is now effectively pushed to the caller (or the
    caller's caller), we would have to check there that the pointer isn't
    NULL. That's a lot of boilerplate to add.

  * And since this is a generic function, I wouldn't trust the caller
    to give a pointer that can be dereferenced right away. This might
    be more subjective though.

So I guess we should make sure that we are consistent, but I'd be in
favor of putting that check in all the functions.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 5f63fc74e265..35b459d186c5 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -333,54 +333,6 @@  drm_get_format_info(struct drm_device *dev,
 EXPORT_SYMBOL(drm_get_format_info);
 
 /**
- * drm_format_plane_width - width of the plane given the first plane
- * @width: width of the first plane
- * @format: pixel format
- * @plane: plane index
- *
- * Returns:
- * The width of @plane, given that the width of the first plane is @width.
- */
-int drm_format_plane_width(int width, uint32_t format, int plane)
-{
-	const struct drm_format_info *info;
-
-	info = drm_format_info(format);
-	if (!info || plane >= info->num_planes)
-		return 0;
-
-	if (plane == 0)
-		return width;
-
-	return width / info->hsub;
-}
-EXPORT_SYMBOL(drm_format_plane_width);
-
-/**
- * drm_format_plane_height - height of the plane given the first plane
- * @height: height of the first plane
- * @format: pixel format
- * @plane: plane index
- *
- * Returns:
- * The height of @plane, given that the height of the first plane is @height.
- */
-int drm_format_plane_height(int height, uint32_t format, int plane)
-{
-	const struct drm_format_info *info;
-
-	info = drm_format_info(format);
-	if (!info || plane >= info->num_planes)
-		return 0;
-
-	if (plane == 0)
-		return height;
-
-	return height / info->vsub;
-}
-EXPORT_SYMBOL(drm_format_plane_height);
-
-/**
  * drm_format_info_block_width - width in pixels of block.
  * @info: pixel format info
  * @plane: plane index
diff --git a/drivers/gpu/drm/meson/meson_overlay.c b/drivers/gpu/drm/meson/meson_overlay.c
index fb8515b2860c..55b3f2f2e608 100644
--- a/drivers/gpu/drm/meson/meson_overlay.c
+++ b/drivers/gpu/drm/meson/meson_overlay.c
@@ -466,8 +466,8 @@  static void meson_overlay_atomic_update(struct drm_plane *plane,
 		priv->viu.vd1_addr2 = gem->paddr + fb->offsets[2];
 		priv->viu.vd1_stride2 = fb->pitches[2];
 		priv->viu.vd1_height2 =
-			drm_format_plane_height(fb->height,
-						fb->format->format, 2);
+			drm_format_info_plane_height(fb->format,
+						fb->height, 2);
 		DRM_DEBUG("plane 2 addr 0x%x stride %d height %d\n",
 			 priv->viu.vd1_addr2,
 			 priv->viu.vd1_stride2,
@@ -478,8 +478,8 @@  static void meson_overlay_atomic_update(struct drm_plane *plane,
 		priv->viu.vd1_addr1 = gem->paddr + fb->offsets[1];
 		priv->viu.vd1_stride1 = fb->pitches[1];
 		priv->viu.vd1_height1 =
-			drm_format_plane_height(fb->height,
-						fb->format->format, 1);
+			drm_format_info_plane_height(fb->format,
+						fb->height, 1);
 		DRM_DEBUG("plane 1 addr 0x%x stride %d height %d\n",
 			 priv->viu.vd1_addr1,
 			 priv->viu.vd1_stride1,
@@ -490,8 +490,8 @@  static void meson_overlay_atomic_update(struct drm_plane *plane,
 		priv->viu.vd1_addr0 = gem->paddr + fb->offsets[0];
 		priv->viu.vd1_stride0 = fb->pitches[0];
 		priv->viu.vd1_height0 =
-			drm_format_plane_height(fb->height,
-						fb->format->format, 0);
+			drm_format_info_plane_height(fb->format,
+						fb->height, 0);
 		DRM_DEBUG("plane 0 addr 0x%x stride %d height %d\n",
 			 priv->viu.vd1_addr0,
 			 priv->viu.vd1_stride0,
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index 6b5a82b31bc4..4ef8ccb5d236 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -277,6 +277,50 @@  int drm_format_info_plane_cpp(const struct drm_format_info *info, int plane)
 	return info->cpp[plane];
 }
 
+/**
+ * drm_format_info_plane_width - width of the plane given the first plane
+ * @format: pixel format info
+ * @width: width of the first plane
+ * @plane: plane index
+ *
+ * Returns:
+ * The width of @plane, given that the width of the first plane is @width.
+ */
+static inline
+int drm_format_info_plane_width(const struct drm_format_info *info, int width,
+				int plane)
+{
+	if (!info || plane >= info->num_planes)
+		return 0;
+
+	if (plane == 0)
+		return width;
+
+	return width / info->hsub;
+}
+
+/**
+ * drm_format_info_plane_height - height of the plane given the first plane
+ * @format: pixel format info
+ * @height: height of the first plane
+ * @plane: plane index
+ *
+ * Returns:
+ * The height of @plane, given that the height of the first plane is @height.
+ */
+static inline
+int drm_format_info_plane_height(const struct drm_format_info *info, int height,
+				 int plane)
+{
+	if (!info || plane >= info->num_planes)
+		return 0;
+
+	if (plane == 0)
+		return height;
+
+	return height / info->vsub;
+}
+
 const struct drm_format_info *__drm_format_info(u32 format);
 const struct drm_format_info *drm_format_info(u32 format);
 const struct drm_format_info *
@@ -285,8 +329,6 @@  drm_get_format_info(struct drm_device *dev,
 uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
 uint32_t drm_driver_legacy_fb_format(struct drm_device *dev,
 				     uint32_t bpp, uint32_t depth);
-int drm_format_plane_width(int width, uint32_t format, int plane);
-int drm_format_plane_height(int height, uint32_t format, int plane);
 unsigned int drm_format_info_block_width(const struct drm_format_info *info,
 					 int plane);
 unsigned int drm_format_info_block_height(const struct drm_format_info *info,