Revert "drm/fb-helper: Reduce READ_ONCE(master) to lockless_dereference"

[cascardo/linux.git] / drivers / gpu / drm / drm_fb_helper.c

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 7c2eb75..0a06f91 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -227,7 +227,7 @@ static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
        g_base = r_base + crtc->gamma_size;
        b_base = g_base + crtc->gamma_size;
 
-       crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size);
+       crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, crtc->gamma_size);
 }
 
 /**
@@ -385,7 +385,7 @@ static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 
        drm_warn_on_modeset_not_all_locked(dev);
 
-       if (fb_helper->atomic)
+       if (dev->mode_config.funcs->atomic_commit)
                return restore_fbdev_mode_atomic(fb_helper);
 
        drm_for_each_plane(plane, dev) {
@@ -464,7 +464,7 @@ static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
 
        /* Sometimes user space wants everything disabled, so don't steal the
         * display if there's a master. */
-       if (dev->primary->master)
+       if (READ_ONCE(dev->master))
                return false;
 
        drm_for_each_crtc(crtc, dev) {
@@ -716,8 +716,6 @@ int drm_fb_helper_init(struct drm_device *dev,
                i++;
        }
 
-       fb_helper->atomic = !!drm_core_check_feature(dev, DRIVER_ATOMIC);
-
        return 0;
 out_free:
        drm_fb_helper_crtc_free(fb_helper);
@@ -1042,7 +1040,6 @@ 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 +1071,10 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
                    !fb_helper->funcs->gamma_get))
                return -EINVAL;
 
-       pindex = regno;
-
-       if (fb->bits_per_pixel == 16) {
-               pindex = regno << 3;
-
-               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);
-                       }
+       WARN_ON(fb->bits_per_pixel != 8);
 
-                       fb_helper->funcs->gamma_get(crtc, &r,
-                                                   &g, &b,
-                                                   pindex >> 1);
+       fb_helper->funcs->gamma_set(crtc, red, green, blue, regno);
 
-                       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;
 }
 
@@ -1373,7 +1342,7 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
                return -EBUSY;
        }
 
-       if (fb_helper->atomic) {
+       if (dev->mode_config.funcs->atomic_commit) {
                ret = pan_display_atomic(var, info);
                goto unlock;
        }
@@ -2000,7 +1969,18 @@ static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
                my_score++;
 
        connector_funcs = connector->helper_private;
-       encoder = connector_funcs->best_encoder(connector);
+
+       /*
+        * If the DRM device implements atomic hooks and ->best_encoder() is
+        * NULL we fallback to the default drm_atomic_helper_best_encoder()
+        * helper.
+        */
+       if (fb_helper->dev->mode_config.funcs->atomic_commit &&
+           !connector_funcs->best_encoder)
+               encoder = drm_atomic_helper_best_encoder(connector);
+       else
+               encoder = connector_funcs->best_encoder(connector);
+
        if (!encoder)
                goto out;