Commit f458579e authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/fb-helper: Instanciate shadow FB if configured in device's mode_config 



Generic framebuffer emulation uses a shadow buffer for framebuffers with
dirty() function. If drivers want to use the shadow FB without such a
function, they can now set prefer_shadow or prefer_shadow_fbdev in their
mode_config structures. The former flag is exported to userspace, the
latter flag is fbdev-only.

v3:
	* only schedule dirty worker if fbdev uses shadow fb
	* test shadow fb settings with boolean operators
	* use bool for struct drm_mode_config.prefer_shadow_fbdev
	* fix documentation comments

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Tested-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/315834/
parent cf1ca9ae

drivers/gpu/drm/drm_fb_helper.c

+15 −3
Original line number Diff line number Diff line
@@ -421,7 +421,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) 
				return;

			drm_fb_helper_dirty_blit_real(helper, &clip_copy);

		}

		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);

		if (helper->fb->funcs->dirty)

			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,

						 &clip_copy, 1);



		if (helper->buffer)

			drm_client_buffer_vunmap(helper->buffer);
@@ -613,6 +615,16 @@ void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper) 
}

EXPORT_SYMBOL(drm_fb_helper_unlink_fbi);



static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)

{

	struct drm_device *dev = fb_helper->dev;

	struct drm_framebuffer *fb = fb_helper->fb;



	return dev->mode_config.prefer_shadow_fbdev ||

	       dev->mode_config.prefer_shadow ||

	       fb->funcs->dirty;

}



static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,

				u32 width, u32 height)

{
@@ -620,7 +632,7 @@ static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y, 
	struct drm_clip_rect *clip = &helper->dirty_clip;

	unsigned long flags;



	if (!helper->fb->funcs->dirty)

	if (!drm_fbdev_use_shadow_fb(helper))

		return;



	spin_lock_irqsave(&helper->dirty_lock, flags);
@@ -2213,7 +2225,7 @@ int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, 


	drm_fb_helper_fill_info(fbi, fb_helper, sizes);



	if (fb->funcs->dirty) {

	if (drm_fbdev_use_shadow_fb(fb_helper)) {

		struct fb_ops *fbops;

		void *shadow;

include/drm/drm_mode_config.h

+7 −0
Original line number Diff line number Diff line
@@ -852,6 +852,13 @@ struct drm_mode_config { 
	/* dumb ioctl parameters */

	uint32_t preferred_depth, prefer_shadow;



	/**

	 * @prefer_shadow_fbdev:

	 *

	 * Hint to framebuffer emulation to prefer shadow-fb rendering.

	 */

	bool prefer_shadow_fbdev;



	/**

	 * @quirk_addfb_prefer_xbgr_30bpp:

	 *

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