Re: [PATCH v6 1/3] drm/vkms: Decouple crc operations from composer

Hi,

On 08/30, Rodrigo Siqueira wrote:

In the vkms_composer.c, some of the functions related to CRC and compose have interdependence between each other. This patch reworks some functions inside vkms_composer to make crc and composer computation decoupled.

This patch is preparation work for making vkms able to support new features.

Tested-by: Melissa Wen melissa.srw@gmail.com Signed-off-by: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com

---

drivers/gpu/drm/vkms/vkms_composer.c | 49 ++++++++++++++++------------ 1 file changed, 29 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c index eaecc5a6c5db..f67d1baf1942 100644 --- a/drivers/gpu/drm/vkms/vkms_composer.c +++ b/drivers/gpu/drm/vkms/vkms_composer.c @@ -131,35 +131,31 @@ static void compose_cursor(struct vkms_composer *cursor_composer, primary_composer, cursor_composer); }

-static uint32_t _vkms_get_crc(struct vkms_composer *primary_composer,

• 	      struct vkms_composer *cursor_composer)
  

+static int compose_planes(void **vaddr_out,

• 	  struct vkms_composer *primary_composer,
  

• 	  struct vkms_composer *cursor_composer)
  

{ struct drm_framebuffer *fb = &primary_composer->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;

• if (!vaddr_out) {

• DRM_ERROR("Failed to allocate memory for output frame.");
  

• return 0;
  

• if (!*vaddr_out) {

• *vaddr_out = kzalloc(vkms_obj->gem.size, GFP_KERNEL);
  

• if (!*vaddr_out) {
  

• 	DRM_ERROR("Cannot allocate memory for output frame.");
  

• 	return -ENOMEM;
  

• }
  

  }

• if (WARN_ON(!vkms_obj->vaddr)) {

• kfree(vaddr_out);
  

• return crc;
  

• }

• if (WARN_ON(!vkms_obj->vaddr))

• return -EINVAL;
  
  

• memcpy(vaddr_out, vkms_obj->vaddr, vkms_obj->gem.size);

• memcpy(*vaddr_out, vkms_obj->vaddr, vkms_obj->gem.size);

  if (cursor_composer)

• compose_cursor(cursor_composer, primary_composer, vaddr_out);
  

• compose_cursor(cursor_composer, primary_composer, *vaddr_out);
  
  

• crc = compute_crc(vaddr_out, primary_composer);
• kfree(vaddr_out);
• return crc;

• return 0;

}

/** @@ -180,9 +176,11 @@ void vkms_composer_worker(struct work_struct *work) struct vkms_output *out = drm_crtc_to_vkms_output(crtc); struct vkms_composer *primary_composer = NULL; struct vkms_composer *cursor_composer = NULL;

• void *vaddr_out = NULL; u32 crc32 = 0; u64 frame_start, frame_end; bool crc_pending;

• int ret;

  spin_lock_irq(&out->composer_lock); frame_start = crtc_state->frame_start;

@@ -206,14 +204,25 @@ void vkms_composer_worker(struct work_struct *work) if (crtc_state->num_active_planes == 2) cursor_composer = crtc_state->active_planes[1]->composer;

• if (primary_composer)

• crc32 = _vkms_get_crc(primary_composer, cursor_composer);
  

• if (!primary_composer)

• return;
  

• ret = compose_planes(&vaddr_out, primary_composer, cursor_composer);

• if (ret) {

• if (ret == -EINVAL)
  

• 	kfree(vaddr_out);
  

• return;
  

• }

• crc32 = compute_crc(vaddr_out, primary_composer);

  /*

  • The worker can fall behind the vblank hrtimer, make sure we catch up.

  */ while (frame_start <= frame_end) drm_crtc_add_crc_entry(crtc, true, frame_start++, &crc32);

• kfree(vaddr_out);

}

static const char * const pipe_crc_sources[] = {"auto"};

2.28.0

I noticed two improvements: for a pre-existing op (alloc), but that could affect the logic of the next patch; and another one (kfree - release vaddr_out earlier, when it’s no longer needed) that you also adjusted in the next one and is harmless here.

So, looking as a preparation for the writeback patch, I tested and consider that this rework keeps operations stable here.

Reviewed-by: Melissa Wen melissa.srw@gmail.com