[PATCH 6/6] drm/fb-helper: Use fb_{cfb,sys}_{read, write}()

[Geert Uytterhoeven]

Hi Thomas,

On Tue, Apr 25, 2023 at 4:28 PM Thomas Zimmermann <tzimmermann at suse.de> wrote:
> Implement DRM fbdev helpers for reading and writing framebuffer
> memory with the respective fbdev functions. Removes duplicate
> code.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>

Thanks for your patch!

> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c

> @@ -816,21 +727,10 @@ static ssize_t drm_fb_helper_read_screen_buffer(struct fb_info *info, char __use
>  ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
>                                size_t count, loff_t *ppos)
>  {
> -       return __drm_fb_helper_read(info, buf, count, ppos, drm_fb_helper_read_screen_buffer);
> +       return fb_sys_read(info, buf, count, ppos);
>  }
>  EXPORT_SYMBOL(drm_fb_helper_sys_read);

I guess drm_fb_helper_sys_read() can just be removed?

> @@ -849,7 +749,7 @@ ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
>         ssize_t ret;
>         struct drm_rect damage_area;
>
> -       ret = __drm_fb_helper_write(info, buf, count, ppos, drm_fb_helper_write_screen_buffer);
> +       ret = fb_sys_write(info, buf, count, ppos);
>         if (ret <= 0)
>                 return ret;
>

drm_fb_helper_sys_write() cannot be removed yet, because it does damage
handling below.  If the fb_ops.fb_sync() callback would be enhanced to pass
a region, drm_fb_helper could implement .fb_sync() instead of .fb_write().

Likewise for the "cfb" (which is a misnomer) variants below.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds