drm/omap: fix display SYNC/DE flags

At the moment VSYNC/HSYNC/DE high/low flags set by the panel/encoder
drivers get lost when the videotimings are translated to DRM's
videomode, as DRM's mode does not have corresponding flags.

DRM has bus-flags for this purpose, and while it lacks a few flags at
the moment, it should be used here. However, until we rewrite omapdrm's
device model, using bus-flags is rather difficult.

As a short term fix, this patch makes sure that every time the videomode
is set in omap_crtc_mode_set_nofb(), the driver asks for the SYNC/DE
flags from the panel/encoder drivers, and thus we get the correct flags
into use.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 37 insertions, 3 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index 1db96b077ae8..4f03f74685f0 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -373,6 +373,11 @@ static void omap_crtc_mode_set_nofb(struct drm_crtc *crtc)
 {
         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
         struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+        struct omap_drm_private *priv = crtc->dev->dev_private;
+        const u32 flags_mask = DISPLAY_FLAGS_DE_HIGH | DISPLAY_FLAGS_DE_LOW |
+                DISPLAY_FLAGS_PIXDATA_POSEDGE | DISPLAY_FLAGS_PIXDATA_NEGEDGE |
+                DISPLAY_FLAGS_SYNC_POSEDGE | DISPLAY_FLAGS_SYNC_NEGEDGE;
+        unsigned int i;
 
         DBG("%s: set mode: %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x",
             omap_crtc->name, mode->base.id, mode->name,
@@ -382,9 +387,38 @@ static void omap_crtc_mode_set_nofb(struct drm_crtc *crtc)
             mode->type, mode->flags);
 
         drm_display_mode_to_videomode(mode, &omap_crtc->vm);
-        omap_crtc->vm.flags |= DISPLAY_FLAGS_DE_HIGH |
-                               DISPLAY_FLAGS_PIXDATA_POSEDGE |
-                               DISPLAY_FLAGS_SYNC_NEGEDGE;
+
+        /*
+         * HACK: This fixes the vm flags.
+         * struct drm_display_mode does not contain the VSYNC/HSYNC/DE flags
+         * and they get lost when converting back and forth between
+         * struct drm_display_mode and struct videomode. The hack below
+         * goes and fetches the missing flags from the panel drivers.
+         *
+         * Correct solution would be to use DRM's bus-flags, but that's not
+         * easily possible before the omapdrm's panel/encoder driver model
+         * has been changed to the DRM model.
+         */
+
+        for (i = 0; i < priv->num_encoders; ++i) {
+                struct drm_encoder *encoder = priv->encoders[i];
+
+                if (encoder->crtc == crtc) {
+                        struct omap_dss_device *dssdev;
+
+                        dssdev = omap_encoder_get_dssdev(encoder);
+
+                        if (dssdev) {
+                                struct videomode vm = {0};
+
+                                dssdev->driver->get_timings(dssdev, &vm);
+
+                                omap_crtc->vm.flags |= vm.flags & flags_mask;
+                        }
+
+                        break;
+                }
+        }
 }
 
 static int omap_crtc_atomic_check(struct drm_crtc *crtc,