drm/udl: Move log-cpp code out of udl_damage_handler()

Computing the cpp value's logarithm in a separate helper function makes
the damage-handler code more readable.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191206085954.9697-6-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index cc2a09a..482786e 100644 (file)
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -58,6 +58,13 @@ static uint16_t rgb16(uint32_t col)
 }
 #endif
 
+static long udl_log_cpp(unsigned int cpp)
+{
+       if (WARN_ON(!is_power_of_2(cpp)))
+               return -EINVAL;
+       return __ffs(cpp);
+}
+
 static int udl_aligned_damage_clip(struct drm_rect *clip, int x, int y,
                                   int width, int height)
 {
@@ -92,11 +99,6 @@ int udl_handle_damage(struct drm_framebuffer *fb, int x, int y,
        int log_bpp;
        void *vaddr;
 
-       if (WARN_ON(!is_power_of_2(fb->format->cpp[0])))
-               return -EINVAL;
-
-       log_bpp = __ffs(fb->format->cpp[0]);
-
        spin_lock(&udl->active_fb_16_lock);
        if (udl->active_fb_16 != fb) {
                spin_unlock(&udl->active_fb_16_lock);
@@ -104,6 +106,11 @@ int udl_handle_damage(struct drm_framebuffer *fb, int x, int y,
        }
        spin_unlock(&udl->active_fb_16_lock);
 
+       ret = udl_log_cpp(fb->format->cpp[0]);
+       if (ret < 0)
+               return ret;
+       log_bpp = ret;
+
        ret = udl_aligned_damage_clip(&clip, x, y, width, height);
        if (ret)
                return ret;