drm: crtc_helper: Update hwmode before mode_set call

Just as we provide crtc->mode pre-populated with the requested mode,
move adjusted_mode into hwmode before we call the crtc's mode_set,
making sure to restore it on failure.

Allows drivers which thoughtlessly discard adjusted_mode in their
mode_set hooks (e.g. Exynos) to use hwmode directly, and also provides
some neat symmetry with crtc->mode.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 3053aab968f9..dd895c409ca3 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -270,7 +270,7 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
                               struct drm_framebuffer *old_fb)
 {
         struct drm_device *dev = crtc->dev;
-        struct drm_display_mode *adjusted_mode, saved_mode;
+        struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
         struct drm_encoder_helper_funcs *encoder_funcs;
         int saved_x, saved_y;
@@ -292,6 +292,7 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
         }
 
         saved_mode = crtc->mode;
+        saved_hwmode = crtc->hwmode;
         saved_x = crtc->x;
         saved_y = crtc->y;
 
@@ -334,6 +335,8 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
         }
         DRM_DEBUG_KMS("[CRTC:%d]\n", crtc->base.id);
 
+        crtc->hwmode = *adjusted_mode;
+
         /* Prepare the encoders and CRTCs before setting the mode. */
         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 
@@ -396,9 +399,6 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
                         encoder->bridge->funcs->enable(encoder->bridge);
         }
 
-        /* Store real post-adjustment hardware mode. */
-        crtc->hwmode = *adjusted_mode;
-
         /* Calculate and store various constants which
          * are later needed by vblank and swap-completion
          * timestamping. They are derived from true hwmode.
@@ -411,6 +411,7 @@ done:
         if (!ret) {
                 crtc->enabled = saved_enabled;
                 crtc->mode = saved_mode;
+                crtc->hwmode = saved_hwmode;
                 crtc->x = saved_x;
                 crtc->y = saved_y;
         }