[RFC PATCH 04/37] drm: crtc_helper: Update hwmode before mode_set call

[Daniel Stone]

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 at collabora.com>
---
 drivers/gpu/drm/drm_crtc_helper.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc_helper.c 
b/drivers/gpu/drm/drm_crtc_helper.c
index 3053aab..dd895c4 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;
        }
-- 
2.3.2