[PATCH 0/2] drm: CMA fbdev stride adjustment

[PATCH 0/2] drm: CMA fbdev stride adjustment

[Rob Herring]

I'm working on a DRM driver for PXA1928. Other than a stride alignment 
requirement of 16 bytes, I have no other reason not to use fbdev_cma. 
While I can adjust the stride for drm_gem_cma_dumb_create, I cannot do 
the same for drm_fbdev_cma_create without duplicating a bunch of code. 
This series allows fbdev_cma users to override the fb_probe function, so 
the stride can be adjusted.

It appears to me that rcar-du has a bug that it doesn't handle alignment 
requirements for this case as well. Probably just getting lucky with 
tested resolutions/bpp.

Also, AFAICT the Rockchip driver has no real reason to use a custom GEM 
allocator instead of the CMA one. It sets the DMA_ATTR_NO_KERNEL_MAPPING 
DMA attr, but that could easily be supported by the CMA allocator.

Rob

Rob Herring (2):
  drm/cma: allow custom fb helper functions
  drm/cma: allow adjusting the pitch for CMA fbdev

 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c |  2 +-
 drivers/gpu/drm/drm_fb_cma_helper.c          | 13 ++++++++++---
 drivers/gpu/drm/imx/imx-drm-core.c           |  2 +-
 drivers/gpu/drm/rcar-du/rcar_du_kms.c        |  3 ++-
 drivers/gpu/drm/sti/sti_drm_drv.c            |  2 +-
 drivers/gpu/drm/tilcdc/tilcdc_drv.c          |  2 +-
 include/drm/drm_fb_cma_helper.h              |  7 +++++++
 include/drm/drm_fb_helper.h                  |  1 +
 8 files changed, 24 insertions(+), 8 deletions(-)

-- 
2.1.4

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[PATCH 1/2] drm/cma: allow custom fb helper functions

[Rob Herring]

Allow drivers to provide custom drm_fb_helper_funcs overriding the
default functions.

Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c |  2 +-
 drivers/gpu/drm/drm_fb_cma_helper.c          | 10 ++++++++--
 drivers/gpu/drm/imx/imx-drm-core.c           |  2 +-
 drivers/gpu/drm/rcar-du/rcar_du_kms.c        |  3 ++-
 drivers/gpu/drm/sti/sti_drm_drv.c            |  2 +-
 drivers/gpu/drm/tilcdc/tilcdc_drv.c          |  2 +-
 include/drm/drm_fb_cma_helper.h              |  7 +++++++
 7 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 6fad1f9..f8047ab 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -211,7 +211,7 @@ static void atmel_hlcdc_fb_output_poll_changed(struct drm_device *dev)
 	if (dc->fbdev) {
 		drm_fbdev_cma_hotplug_event(dc->fbdev);
 	} else {
-		dc->fbdev = drm_fbdev_cma_init(dev, 24,
+		dc->fbdev = drm_fbdev_cma_init(dev, NULL, 24,
 				dev->mode_config.num_crtc,
 				dev->mode_config.num_connector);
 		if (IS_ERR(dc->fbdev))
diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
index 5c1aca4..f7751a2 100644
--- a/drivers/gpu/drm/drm_fb_cma_helper.c
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -244,7 +244,7 @@ static struct fb_ops drm_fbdev_cma_ops = {
 	.fb_setcmap	= drm_fb_helper_setcmap,
 };
 
-static int drm_fbdev_cma_create(struct drm_fb_helper *helper,
+int drm_fbdev_cma_create(struct drm_fb_helper *helper,
 	struct drm_fb_helper_surface_size *sizes)
 {
 	struct drm_fbdev_cma *fbdev_cma = to_fbdev_cma(helper);
@@ -326,6 +326,7 @@ err_drm_gem_cma_free_object:
 	drm_gem_cma_free_object(&obj->base);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(drm_fbdev_cma_create);
 
 static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
 	.fb_probe = drm_fbdev_cma_create,
@@ -334,6 +335,7 @@ static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
 /**
  * drm_fbdev_cma_init() - Allocate and initializes a drm_fbdev_cma struct
  * @dev: DRM device
+ * @helper_funcs: Optional driver specific drm_fb_helper_funcs
  * @preferred_bpp: Preferred bits per pixel for the device
  * @num_crtc: Number of CRTCs
  * @max_conn_count: Maximum number of connectors
@@ -341,6 +343,7 @@ static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
  * Returns a newly allocated drm_fbdev_cma struct or a ERR_PTR.
  */
 struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
+	const struct drm_fb_helper_funcs *helper_funcs,
 	unsigned int preferred_bpp, unsigned int num_crtc,
 	unsigned int max_conn_count)
 {
@@ -356,7 +359,10 @@ struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
 
 	helper = &fbdev_cma->fb_helper;
 
-	drm_fb_helper_prepare(dev, helper, &drm_fb_cma_helper_funcs);
+	if (!helper_funcs)
+		helper_funcs = &drm_fb_cma_helper_funcs;
+
+	drm_fb_helper_prepare(dev, helper, helper_funcs);
 
 	ret = drm_fb_helper_init(dev, helper, num_crtc, max_conn_count);
 	if (ret < 0) {
diff --git a/drivers/gpu/drm/imx/imx-drm-core.c b/drivers/gpu/drm/imx/imx-drm-core.c
index 74f505b..4da348b 100644
--- a/drivers/gpu/drm/imx/imx-drm-core.c
+++ b/drivers/gpu/drm/imx/imx-drm-core.c
@@ -313,7 +313,7 @@ static int imx_drm_driver_load(struct drm_device *drm, unsigned long flags)
 		dev_warn(drm->dev, "Invalid legacyfb_depth.  Defaulting to 16bpp\n");
 		legacyfb_depth = 16;
 	}
-	imxdrm->fbhelper = drm_fbdev_cma_init(drm, legacyfb_depth,
+	imxdrm->fbhelper = drm_fbdev_cma_init(drm, NULL, legacyfb_depth,
 				drm->mode_config.num_crtc, MAX_CRTC);
 	if (IS_ERR(imxdrm->fbhelper)) {
 		ret = PTR_ERR(imxdrm->fbhelper);
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 56518eb..7546408 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -828,7 +828,8 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 	drm_kms_helper_poll_init(dev);
 
 	if (dev->mode_config.num_connector) {
-		fbdev = drm_fbdev_cma_init(dev, 32, dev->mode_config.num_crtc,
+		fbdev = drm_fbdev_cma_init(dev, NULL, 32,
+					   dev->mode_config.num_crtc,
 					   dev->mode_config.num_connector);
 		if (IS_ERR(fbdev))
 			return PTR_ERR(fbdev);
diff --git a/drivers/gpu/drm/sti/sti_drm_drv.c b/drivers/gpu/drm/sti/sti_drm_drv.c
index 59d558b..64d1fb1 100644
--- a/drivers/gpu/drm/sti/sti_drm_drv.c
+++ b/drivers/gpu/drm/sti/sti_drm_drv.c
@@ -161,7 +161,7 @@ static int sti_drm_load(struct drm_device *dev, unsigned long flags)
 	drm_mode_config_reset(dev);
 
 #ifdef CONFIG_DRM_STI_FBDEV
-	drm_fbdev_cma_init(dev, 32,
+	drm_fbdev_cma_init(dev, NULL, 32,
 		   dev->mode_config.num_crtc,
 		   dev->mode_config.num_connector);
 #endif
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 0f283a3..cab0df6 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -294,7 +294,7 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 			break;
 	}
 
-	priv->fbdev = drm_fbdev_cma_init(dev, bpp,
+	priv->fbdev = drm_fbdev_cma_init(dev, NULL, bpp,
 			dev->mode_config.num_crtc,
 			dev->mode_config.num_connector);
 	if (IS_ERR(priv->fbdev)) {
diff --git a/include/drm/drm_fb_cma_helper.h b/include/drm/drm_fb_cma_helper.h
index c54cf3d..ef691ab 100644
--- a/include/drm/drm_fb_cma_helper.h
+++ b/include/drm/drm_fb_cma_helper.h
@@ -8,12 +8,19 @@ struct drm_framebuffer;
 struct drm_device;
 struct drm_file;
 struct drm_mode_fb_cmd2;
+struct drm_fb_helper_funcs;
+struct drm_fb_helper;
+struct drm_fb_helper_surface_size;
 
 struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
+	const struct drm_fb_helper_funcs *helper_funcs,
 	unsigned int preferred_bpp, unsigned int num_crtc,
 	unsigned int max_conn_count);
 void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma);
 
+int drm_fbdev_cma_create(struct drm_fb_helper *helper,
+	struct drm_fb_helper_surface_size *sizes);
+
 void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma);
 void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma);
 
-- 
2.1.4

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[PATCH 2/2] drm/cma: allow adjusting the pitch for CMA fbdev

[Rob Herring]

Some hardware has pitch alignment requirements, but there is no way to
set the pitch for CMA fbdev other than completely replacing
drm_fbdev_cma_create. Add the pitch and allow drivers to adjust it
before calling drm_fbdev_cma_create.

Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/gpu/drm/drm_fb_cma_helper.c | 3 ++-
 include/drm/drm_fb_helper.h         | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
index f7751a2..b393e5c 100644
--- a/drivers/gpu/drm/drm_fb_cma_helper.c
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -266,7 +266,8 @@ int drm_fbdev_cma_create(struct drm_fb_helper *helper,
 
 	mode_cmd.width = sizes->surface_width;
 	mode_cmd.height = sizes->surface_height;
-	mode_cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
+	mode_cmd.pitches[0] = sizes->surface_pitch ?
+		sizes->surface_pitch : sizes->surface_width * bytes_per_pixel;
 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 		sizes->surface_depth);
 
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 0dfd94def..8072c4f 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -70,6 +70,7 @@ struct drm_fb_helper_surface_size {
 	u32 surface_height;
 	u32 surface_bpp;
 	u32 surface_depth;
+	u32 surface_pitch;
 };
 
 /**
-- 
2.1.4

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Re: [PATCH 0/2] drm: CMA fbdev stride adjustment

[Daniel Vetter]

On Wed, Aug 12, 2015 at 03:52:12PM -0500, Rob Herring wrote:
> I'm working on a DRM driver for PXA1928. Other than a stride alignment 
> requirement of 16 bytes, I have no other reason not to use fbdev_cma. 
> While I can adjust the stride for drm_gem_cma_dumb_create, I cannot do 
> the same for drm_fbdev_cma_create without duplicating a bunch of code. 
> This series allows fbdev_cma users to override the fb_probe function, so 
> the stride can be adjusted.
> 
> It appears to me that rcar-du has a bug that it doesn't handle alignment 
> requirements for this case as well. Probably just getting lucky with 
> tested resolutions/bpp.
> 
> Also, AFAICT the Rockchip driver has no real reason to use a custom GEM 
> allocator instead of the CMA one. It sets the DMA_ATTR_NO_KERNEL_MAPPING 
> DMA attr, but that could easily be supported by the CMA allocator.

I think it'd be easier to review this with the driver at hand. That's also
generally the requirement for merging new code - it needs an in-kernel
user.
-Daniel

> 
> Rob
> 
> Rob Herring (2):
>   drm/cma: allow custom fb helper functions
>   drm/cma: allow adjusting the pitch for CMA fbdev
> 
>  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c |  2 +-
>  drivers/gpu/drm/drm_fb_cma_helper.c          | 13 ++++++++++---
>  drivers/gpu/drm/imx/imx-drm-core.c           |  2 +-
>  drivers/gpu/drm/rcar-du/rcar_du_kms.c        |  3 ++-
>  drivers/gpu/drm/sti/sti_drm_drv.c            |  2 +-
>  drivers/gpu/drm/tilcdc/tilcdc_drv.c          |  2 +-
>  include/drm/drm_fb_cma_helper.h              |  7 +++++++
>  include/drm/drm_fb_helper.h                  |  1 +
>  8 files changed, 24 insertions(+), 8 deletions(-)
> 
> -- 
> 2.1.4
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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