Re: [PATCH 2/2] drm/vkms: Compute CRC with Cursor Plane

[Haneen Mohammed <hamohammed.sa@gmail.com>]

On Tue, Aug 07, 2018 at 06:33:36PM +0200, Daniel Vetter wrote:
> On Mon, Aug 06, 2018 at 06:58:29AM +0300, Haneen Mohammed wrote:
> > This patch compute CRC for output frame with cursor and primary plane.
> > Blend cursor with primary plane and compute CRC on the resulted frame.
> > 
> > Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
> 
> Nice!
> 
> I assume with this you're passing all the crc based cursor tests in igt?
> If so, please mention this in the commit message, so that there's a record
> of the testing done on this.
> 

Sure, I'll update the commit message.
Is there any other change I should add/fix to this patchset?

> One fairly huge gap we iirc have in our cursor testing is that there's not
> much (if any?) alpha blending coverage. We kinda need that to make sure
> this all works correctly. The usual trick is to only check the extreme
> alpha values, i.e. fully opaque and fully transparent, since intermediate
> values are affected by hw-specific rounding modes.
> > ---
> >  drivers/gpu/drm/vkms/vkms_crc.c   | 149 +++++++++++++++++++++++++-----
> >  drivers/gpu/drm/vkms/vkms_drv.h   |   5 +-
> >  drivers/gpu/drm/vkms/vkms_plane.c |  10 +-
> >  3 files changed, 137 insertions(+), 27 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/vkms/vkms_crc.c b/drivers/gpu/drm/vkms/vkms_crc.c
> > index 37d717f38e3c..4853a739ae5a 100644
> > --- a/drivers/gpu/drm/vkms/vkms_crc.c
> > +++ b/drivers/gpu/drm/vkms/vkms_crc.c
> > @@ -1,36 +1,137 @@
> >  // SPDX-License-Identifier: GPL-2.0
> >  #include "vkms_drv.h"
> >  #include <linux/crc32.h>
> > +#include <drm/drm_atomic.h>
> > +#include <drm/drm_atomic_helper.h>
> >  #include <drm/drm_gem_framebuffer_helper.h>
> >  
> > -static uint32_t _vkms_get_crc(struct vkms_crc_data *crc_data)
> > +/**
> > + * compute_crc - Compute CRC value on output frame
> > + *
> > + * @vaddr_out: address to final framebuffer
> > + * @crc_out: framebuffer's metadata
> > + *
> > + * returns CRC value computed using crc32 on the visible portion of
> > + * the final framebuffer at vaddr_out
> > + */
> > +static uint32_t compute_crc(void *vaddr_out, struct vkms_crc_data *crc_out)
> >  {
> > -	struct drm_framebuffer *fb = &crc_data->fb;
> > +	int i, src_offset;
> > +	int x_src = crc_out->src.x1 >> 16;
> > +	int y_src = crc_out->src.y1 >> 16;
> > +	int h_src = drm_rect_height(&crc_out->src) >> 16;
> > +	int w_src = drm_rect_width(&crc_out->src) >> 16;
> > +	int size_byte = w_src * crc_out->cpp;
> > +	u32 crc = 0;
> > +
> > +	for (i = y_src; i < y_src + h_src; i++) {
> > +		src_offset = crc_out->offset
> > +			     + (i * crc_out->pitch)
> > +			     + (x_src * crc_out->cpp);
> > +		crc = crc32_le(crc, vaddr_out + src_offset, size_byte);
> > +	}
> > +
> > +	return crc;
> > +}
> > +
> > +/**
> > + * blend - belnd value at vaddr_src with value at vaddr_dst
> > + * @vaddr_dst: destination address
> > + * @vaddr_src: source address
> > + * @crc_dst: destination framebuffer's metadata
> > + * @crc_src: source framebuffer's metadata
> > + *
> > + * Blend value at vaddr_src with value at vaddr_dst.
> > + * Currently, this function write value at vaddr_src on value
> > + * at vaddr_dst using buffer's metadata to locate the new values
> > + * from vaddr_src and their distenation at vaddr_dst.
> > + *
> > + * Todo: Use the alpha value to blend vaddr_src with vaddr_dst
> > + *	 instead of overwriting it.
> 
> Another todo: We must clear the alpha channel in the result after
> blending. This also applies to the primary plane, where the XRGB for the
> pixel format mandates that we entirely ignore the alpha channel.
> 
> This is also something we should probably have an igt testcase for.
> 
> Since there's a few open ends: How many weeks are left in your outreachy
> internship? We need to make sure that at least all the issues are covered
> in a vkms todo file. Would be great to add that in
> Documentation/gpu/vkms.rst, like we have for other drivers.
> -Daniel
> 

I've one more week! I can use this week to prepare the todo file and
finalize this patch?

Thank you,
Haneen

> > + */
> > +static void blend(void *vaddr_dst, void *vaddr_src,
> > +		  struct vkms_crc_data *crc_dst,
> > +		  struct vkms_crc_data *crc_src)
> > +{
> > +	int i, j, j_dst, i_dst;
> > +	int offset_src, offset_dst;
> > +
> > +	int x_src = crc_src->src.x1 >> 16;
> > +	int y_src = crc_src->src.y1 >> 16;
> > +
> > +	int x_dst = crc_src->dst.x1;
> > +	int y_dst = crc_src->dst.y1;
> > +	int h_dst = drm_rect_height(&crc_src->dst);
> > +	int w_dst = drm_rect_width(&crc_src->dst);
> > +
> > +	int y_limit = y_src + h_dst;
> > +	int x_limit = x_src + w_dst;
> > +
> > +	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
> > +		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
> > +			offset_dst = crc_dst->offset
> > +				     + (i_dst * crc_dst->pitch)
> > +				     + (j_dst++ * crc_dst->cpp);
> > +			offset_src = crc_src->offset
> > +				     + (i * crc_src->pitch)
> > +				     + (j * crc_src->cpp);
> > +
> > +			memcpy(vaddr_dst + offset_dst,
> > +			       vaddr_src + offset_src, sizeof(u32));
> > +		}
> > +		i_dst++;
> > +	}
> > +}
> > +
> > +static void compose_cursor(struct vkms_crc_data *cursor_crc,
> > +			   struct vkms_crc_data *primary_crc, void *vaddr_out)
> > +{
> > +	struct drm_gem_object *cursor_obj;
> > +	struct vkms_gem_object *cursor_vkms_obj;
> > +
> > +	cursor_obj = drm_gem_fb_get_obj(&cursor_crc->fb, 0);
> > +	cursor_vkms_obj = drm_gem_to_vkms_gem(cursor_obj);
> > +
> > +	mutex_lock(&cursor_vkms_obj->pages_lock);
> > +	if (WARN_ON(!cursor_vkms_obj->vaddr))
> > +		goto out;
> > +
> > +	blend(vaddr_out, cursor_vkms_obj->vaddr, primary_crc, cursor_crc);
> > +
> > +out:
> > +	mutex_unlock(&cursor_vkms_obj->pages_lock);
> > +}
> > +
> > +static uint32_t _vkms_get_crc(struct vkms_crc_data *primary_crc,
> > +			      struct vkms_crc_data *cursor_crc)
> > +{
> > +	struct drm_framebuffer *fb = &primary_crc->fb;
> >  	struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
> >  	struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(gem_obj);
> > +	void *vaddr_out = kzalloc(vkms_obj->gem.size, GFP_KERNEL);
> >  	u32 crc = 0;
> > -	int i = 0;
> > -	unsigned int x = crc_data->src.x1 >> 16;
> > -	unsigned int y = crc_data->src.y1 >> 16;
> > -	unsigned int height = drm_rect_height(&crc_data->src) >> 16;
> > -	unsigned int width = drm_rect_width(&crc_data->src) >> 16;
> > -	unsigned int cpp = fb->format->cpp[0];
> > -	unsigned int src_offset;
> > -	unsigned int size_byte = width * cpp;
> > -	void *vaddr;
> >  
> > -	mutex_lock(&vkms_obj->pages_lock);
> > -	vaddr = vkms_obj->vaddr;
> > -	if (WARN_ON(!vaddr))
> > -		goto out;
> > +	if (!vaddr_out) {
> > +		DRM_ERROR("Failed to allocate memory for output frame.");
> > +		return 0;
> > +	}
> >  
> > -	for (i = y; i < y + height; i++) {
> > -		src_offset = fb->offsets[0] + (i * fb->pitches[0]) + (x * cpp);
> > -		crc = crc32_le(crc, vaddr + src_offset, size_byte);
> > +	mutex_lock(&vkms_obj->pages_lock);
> > +	if (WARN_ON(!vkms_obj->vaddr)) {
> > +		mutex_lock(&vkms_obj->pages_lock);
> > +		return crc;
> >  	}
> >  
> > -out:
> > +	memcpy(vaddr_out, vkms_obj->vaddr, vkms_obj->gem.size);
> >  	mutex_unlock(&vkms_obj->pages_lock);
> > +
> > +	if (cursor_crc)
> > +		compose_cursor(cursor_crc, primary_crc, vaddr_out);
> > +
> > +	crc = compute_crc(vaddr_out, primary_crc);
> > +
> > +	kfree(vaddr_out);
> > +
> >  	return crc;
> >  }
> >  
> > @@ -44,8 +145,8 @@ void vkms_crc_work_handle(struct work_struct *work)
> >  	struct vkms_device *vdev = container_of(out, struct vkms_device,
> >  						output);
> >  	struct vkms_crc_data *primary_crc = NULL;
> > +	struct vkms_crc_data *cursor_crc = NULL;
> >  	struct drm_plane *plane;
> > -
> >  	u32 crc32 = 0;
> >  
> >  	drm_for_each_plane(plane, &vdev->drm) {
> > @@ -58,14 +159,14 @@ void vkms_crc_work_handle(struct work_struct *work)
> >  		if (drm_framebuffer_read_refcount(&crc_data->fb) == 0)
> >  			continue;
> >  
> > -		if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
> > +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> >  			primary_crc = crc_data;
> > -			break;
> > -		}
> > +		else
> > +			cursor_crc = crc_data;
> >  	}
> >  
> >  	if (primary_crc)
> > -		crc32 = _vkms_get_crc(primary_crc);
> > +		crc32 = _vkms_get_crc(primary_crc, cursor_crc);
> >  
> >  	drm_crtc_add_crc_entry(crtc, true, crtc_state->n_frame, &crc32);
> >  }
> > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> > index 36e524f791fe..173875dc361e 100644
> > --- a/drivers/gpu/drm/vkms/vkms_drv.h
> > +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> > @@ -25,8 +25,11 @@ static const u32 vkms_cursor_formats[] = {
> >  };
> >  
> >  struct vkms_crc_data {
> > -	struct drm_rect src;
> >  	struct drm_framebuffer fb;
> > +	struct drm_rect src, dst;
> > +	unsigned int offset;
> > +	unsigned int pitch;
> > +	unsigned int cpp;
> >  };
> >  
> >  /**
> > diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> > index 428247d403dc..7041007396ae 100644
> > --- a/drivers/gpu/drm/vkms/vkms_plane.c
> > +++ b/drivers/gpu/drm/vkms/vkms_plane.c
> > @@ -85,16 +85,22 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
> >  				     struct drm_plane_state *old_state)
> >  {
> >  	struct vkms_plane_state *vkms_plane_state;
> > +	struct drm_framebuffer *fb = plane->state->fb;
> >  	struct vkms_crc_data *crc_data;
> >  
> > -	if (!plane->state->crtc || !plane->state->fb)
> > +	if (!plane->state->crtc || !fb)
> >  		return;
> >  
> >  	vkms_plane_state = to_vkms_plane_state(plane->state);
> > +
> >  	crc_data = vkms_plane_state->crc_data;
> >  	memcpy(&crc_data->src, &plane->state->src, sizeof(struct drm_rect));
> > -	memcpy(&crc_data->fb, plane->state->fb, sizeof(struct drm_framebuffer));
> > +	memcpy(&crc_data->dst, &plane->state->dst, sizeof(struct drm_rect));
> > +	memcpy(&crc_data->fb, fb, sizeof(struct drm_framebuffer));
> >  	drm_framebuffer_get(&crc_data->fb);
> > +	crc_data->offset = fb->offsets[0];
> > +	crc_data->pitch = fb->pitches[0];
> > +	crc_data->cpp = fb->format->cpp[0];
> >  }
> >  
> >  static int vkms_plane_atomic_check(struct drm_plane *plane,
> > -- 
> > 2.17.1
> > 
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel