drm/fb-helper: Remove dead code in setcolreg

DRM fbdev emulation only supports pallete_color with depth == 8, and
truecolor with depth > 8. Handling depth == 16 for palettes is hence
dead code, let's remove it.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1459331485-28376-3-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_fb_helper.c

@@ -1042,7 +1042,6 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
 {
 	struct drm_fb_helper *fb_helper = info->par;
 	struct drm_framebuffer *fb = fb_helper->fb;
-	int pindex;
 
 	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
 		u32 *palette;
@@ -1074,38 +1073,10 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
 		    !fb_helper->funcs->gamma_get))
 		return -EINVAL;
 
-	pindex = regno;
+	WARN_ON(fb->bits_per_pixel != 8);
 
-	if (fb->bits_per_pixel == 16) {
-		pindex = regno << 3;
+	fb_helper->funcs->gamma_set(crtc, red, green, blue, regno);
 
-		if (fb->depth == 16 && regno > 63)
-			return -EINVAL;
-		if (fb->depth == 15 && regno > 31)
-			return -EINVAL;
-
-		if (fb->depth == 16) {
-			u16 r, g, b;
-			int i;
-			if (regno < 32) {
-				for (i = 0; i < 8; i++)
-					fb_helper->funcs->gamma_set(crtc, red,
-						green, blue, pindex + i);
-			}
-
-			fb_helper->funcs->gamma_get(crtc, &r,
-						    &g, &b,
-						    pindex >> 1);
-
-			for (i = 0; i < 4; i++)
-				fb_helper->funcs->gamma_set(crtc, r,
-							    green, b,
-							    (pindex >> 1) + i);
-		}
-	}
-
-	if (fb->depth != 16)
-		fb_helper->funcs->gamma_set(crtc, red, green, blue, pindex);
 	return 0;
 }