Am 27.01.22 um 11:26 schrieb Thomas Zimmermann:
> Mark screen buffers in system memory with FB_VIRTFB. Otherwise, the

FBINFO_ is the name. Will be fixed before merging

> buffers are mmap'ed as I/O memory (i.e., VM_IO). For shadow buffers,
> also set the FB_READS_FAST hint.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/drm_fb_helper.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index ed43b987d306..f15127a32f7a 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -2346,6 +2346,7 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>   	fbi->fbops = &drm_fbdev_fb_ops;
>   	fbi->screen_size = sizes->surface_height * fb->pitches[0];
>   	fbi->fix.smem_len = fbi->screen_size;
> +	fbi->flags = FBINFO_DEFAULT;
>   
>   	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
>   
> @@ -2353,19 +2354,21 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>   		fbi->screen_buffer = vzalloc(fbi->screen_size);
>   		if (!fbi->screen_buffer)
>   			return -ENOMEM;
> +		fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
>   
>   		fbi->fbdefio = &drm_fbdev_defio;
> -
>   		fb_deferred_io_init(fbi);
>   	} else {
>   		/* buffer is mapped for HW framebuffer */
>   		ret = drm_client_buffer_vmap(fb_helper->buffer, &map);
>   		if (ret)
>   			return ret;
> -		if (map.is_iomem)
> +		if (map.is_iomem) {
>   			fbi->screen_base = map.vaddr_iomem;
> -		else
> +		} else {
>   			fbi->screen_buffer = map.vaddr;
> +			fbi->flags |= FBINFO_VIRTFB;
> +		}
>   
>   		/*
>   		 * Shamelessly leak the physical address to user-space. As

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev